(note: I do not consider "Dex" Clerics to be "real" Clerics. They would most likely be better on PvP, but such character is designed to play solo, not to support parties)
What you need to be Support/Cleric?
0. To select yourself, just click your name in upper left corner. That's when you want to buff or heal yourself.
P A T I E N C E. This is not class for someone, who wants to enter huge pack of mobs, kill them all in 10 seconds, drink a potion and move further. This is not class for people, who like to solo everything. It is not for people who want to get rich quick. You will party almost all the time, thus amount of loot you get will be lower - make sure that, if you party with stranger, items are set on "orderly", otherwise you will get nothing. With friends, you can split it afterwards, so no big deal.
Most of time is spent on watching party members HP bars and their buffs. In smaller parties, it might seem like easy job, just buff 1-2 people and sit to regain mana, healing occasionaly. Bigger ones - this is where problems start. Keeping 7 people fully buffed is very tiring, especially once you are Cleric. Muse has 5 buffs top, 2 of which are AOE. Cleric has 11, with 5 AOE(3 of which last *very* short). Clerics(not *muse*, but 2nd job already) are in high demand, but don't try to party with 6 ppl, you will only tire yourself and rewards will not be comparable to effort.
Most important thing is INTelligence, improving your buffs(except for Damage Support) and healing spells by roughly 1%/3.15 INT. Now, how much INT to have is dependant on you. Some people get just INT and nothing else. Some add Dex to avoid some hits(although Blessing Armor is usually better). Another good choice is to get some STR to carry sloted shield with good topaz *and* sloted wand, thus giving you even more INT(g7 topaz in shield would be +35, around 11% better buffs).
In short, get INT every level, maybe adding 1 point to STR or DEX if you have spare points. It will be quite a while before you have good topaz to insert into shield(putting +5 there is a waste), so STR might wait. Minimum STR for socketed shield(round shield) is 36, so that would be enough(unless you use +STR items, which isn't really recommended). Also, SEN increases damage for Wands, but it's effects are minimal, critical rate increase gives more damage than +atk from it.
For PvP, that would getting mostly STR as secondary stat, both for extra HP and defence, as well as damage. Every little bit helps, since it might let you live *just* one second longer, which will be enough to cure yourself.
There is not clear % setting here, only thing is that INT must be *much* higher than any other stat.
Wand or Staff - that's old debate. For many levels, Staff is much superior. Higher atk, higher attack speed, higher MP decrease. Even though Wands are ranged, they are slow and have lower damage - not that it matters, since you probably won't fight directly anyway. However, once you get socketed shield, INT bonus from extra topaz is superior to Staffs MP decrease bonus.
For PvP - it's Staff for Staff Stun, unless you're against class you *don't want to meelee with - say Knight. Than just use Wands and hit&run.
Muse shields(books etc.) - these are useless... Really. Only advantage they have is INT requirements instead of STR, meaning you can use them much earlier than normal shields. However, they don't have slots, which is main reason for carrying shield in the first place. Supposedly they can get slots if crafted by Artisan with *very* high Sen, but I have yet to see such item.
Other equipment - two options you should look for. First, +INT. Quite simple, more INT = better support, which is what you're aiming for. In theory, you could wear Visitor Look +6 INT entire game Second good option is 5%MP decrease / +2 INT. Slightly less int than previous option, but 5% MP can be quite a bit with high level buffs - these cost quite a bit and fully buffing one person can cost lots of MP.
That's it, you don't even need to refine anything.
Jewelry - sockets with Topaz. Anything that adds INT is your goal and since Topaz adds INT...
Full Support or not is main question here. Still, you want everything from Meditation tree, except for Curse and Bon(e)fire. For a Full Support Muse, no other skills are needed, maybe level or two in Spell Mastery for MP decrease, and possibly lvl 1 mana bolt for questing purposes(which cost just as much as Curse, but is far superior). Another interesting thing would be Fire ring(just lvl1), to indirectly increase damage done by your party members - however, this mostly helps with big monsters, not some weaklings that die in 3 hits anyway.
If you want to have make more PvP oriented Cleric, you should get both Staff Stun and Lightning. It will take a few skillpoints, but double stun is very good in 1vs1 - you will not have powerful spells like Magicians, especially Silence, but with your buffs you can still do some damage. Mild would also help a bit - damage decrease is surprisignly high, but that's 2 more levels into Spell Mastery, so quite a few SPs. Also, at least 1 lvl of Mana and Icebolt - when boosted by Damage Support they can do reasonable damage and 1 level is fairly cheap. Summons are good in theory, but Phantoms can't hit anything unless buffed and Elemental takes too many SP to be worth of it.
Meditation - your BASIC skill. No big brainer here, you *must* have it at 10 before level 70. More mana, more mana regen, needed for every other skill.
Cure - heals one target and cools down pretty fast. There is no set level you should have in this skill, just level it when you feel that current level is not enough. I had lvl5 at 109 still and it was enough(you simply start healing earlier )
Healing - heals less then Cure, is more expensive, cooldown is longer, BUT heals every party member in range. Plus you can combo Cure-Heal-Cure if needed to quickly heal one person. Again, level when needed.
Lesser Haste - faster running, needed for all offensive buffs. Level 4 is enough, since it lets you get all of them, and further MSPD increase is minimal.
Power Support - THE skill for Support Muse. Higher ATK is what everyone wants, and is one of two main reason for partying with Support Muse in the first place(healing being other one). Get it to 5 as soon as possible. It also works with spells, so make sure you buff Attack Muses as well.
Hit Support - somewhat less important than previous skill, it is still quite helpful, especially if you plan to fight orange/red/purple monsters or maybe some hawkers on PVP. Lvl 3 is max for Muse, and helps a lot. It also works with spells - these *do* miss on red/purple mobs, so buff Attack Muses.
Blessing - good defensive buff, especially to Hawkers and yourself - extra HP is very useful. Level 5 is enough to get you all other defensive buffs if you want them, if not, just get one and focus on offensive skills after you become a Cleric.
Enchant Armor - it may last short, but defense bonus is huge. Even level 1 is good for some nasty situations, you need level 5 for two next buffs. Get at least level 1 if you don't want them.
Blessed Mind - quite possibly weakest buff, it gives additional mana, but you still have to use potion to regain it. It is only useful when party levels up, which isn't really often. ONLY get it if you want Evasion Aura, otherwise it is waste of SP.
Bonfire - amount of mana restored is low, and good party rarely has time to stay in one place anyway. If you *really* want it, get it to some higher level, where it would actually matter, otherwise, it is waste of SP.
Curse - this spell is probably worst attack spell in game. Low damage, low chance of poisoning target, low poison duration. DON'T GET IT. Just get mana bolt instead if you really want to.
So, to sum up, by level 70 you should have:
Meditation - 10
Cure - 5
Healing - 5
Lesser Haste - 4
Power Support - 5
Hit Support - 3
Blessing - 5 - look below
Enchant Armor - 4 - only if you want to haveDefense/Magical Aura
Blessed Mind - only if you *really* want Evasion Aura - 2
Anything else is optional.
Battle Support - get one level right after 70 and leave it there. Leveling this skill is best left for later, when your INT will be high enough to give +4ASPD per level, which is actually notable. Still, at level one it give around 30, which is very good.
Damage Support - THE skill for Cleric. Level 1 adds 14% damage to every attack and offensive skill, which isn't seen in ATK increase, but is added when damage is inflicted. As for maxing it, each level adds 2%(and 10 - 3%), so you should think if it is really worth of it. It's effect increase anyway, since character increase their ATK every level(at least they should ). Needs 19 Meditation for lvl 10 Power Support.
Critical Support - not as good as Damage Support, since skills don't critical, and by the time you get it, people will probably use them *very* often. It is mostly helpful with fast attacking character(raiders) or those without many combat skills(Artisans). Also, it helps with summons, since those use mostly physical attacks. Needs 20 Meditation for lvl 10 Hitting Support.
Defense Aura - even level one is good, since +40DEF for entire party for 30SP is quite good trade. Unfortunately, duration is shorter than other buffs(which is problem with all 3 Auras)
Magical Aura - less useful than previous one, but helps with some stronger monster, like Tyrants/Mammoths/Behemoths/Astarots. It is also said that it improves chances of resisting debuffs from ghosts/other players. 1 level is enough, since normal DEF *also* reduces damage from spells(even though it sounds stupid)
Evasion Aura - that skill would be good if it didn't have such horrible prerequisite. AVO bonus it gives is not really enough to let low DEX character avoid much, it mostly helps them against blue/green monsters. For hawkers, it could help more.
Ressurection - ideally, no one should die, but, as we all know, "sh7t" or, in most cases, triple cast from mammoths, happens. If you want to get it, get at least level 2, since it doesn't recover any EXP on level 1. Also, DO NOT CAST IT NEAR AOE USING MOBS. Ask other party members to draw it away or do it yourself with Blessing Armor. There is nothing more annoying then getting ressurected and getting killed again by AOE before you could heal.
Purify - it might seem a waste at first, since there aren't many debuffs worth dispelling, but you will appreciate it when your main tanker gets surrounded by enemies he could easily tank normally, and then gets -DEF and -AVO(tested *many* times against Goblin Guardian as well as Astarots;) ) Helps against Tirwins/Elect Ghost as well, even -DEF from BK. 1 level won't hurt(much). Also, certain monsters on Eldeon use Silence - so if your main fighter gets Silenced, you know what to do.
Sometimes you want to solo - maybe to make some extra cash in temple or whatever. This is where summons capsules come handy. Just ask your friends to give them to you if they find it. Fully buffed summon is sometimes stronger than you, has more hp, and doesn't cost any SP, unlike Phantoms(which miss just about everything on later levels) or Elemental.
5. Where to level?
Now that's a easy one - you level where your party wants to Good thing about Cleric is that you can be lowest level in party and still contribute the most(just make sure exp division is equal if partying with *much* higher level people, or risk doesn't compare with rewards). Example, I went to GoS below level 60 and did pretty well there - it all depends on party members. I started going on Elder Mammoths before level 90. Astarots - below 100. Your level is not important, your party members are. And your buffs, obviously.
6. How to get rich?
Very simple, party with Bourg and go to temple. With your buffs he will kill fast and extra drops add fast, letting you get few millions in one day in t2/3. I learned about it too late to benefit - it was my clanmate's Cleric(lower level^^) who did that and got much richer than me
If you don't feel like leveling and just want to wait a while doing nothing - go to some "weaker" areas and buff people there for cash While most of them will only "buff pls" you, some of them might recognize your talent and give you some pots or cash. This is, of course, not a real method of becoming rich, just something to do in your spare time, that can also bring cash. Careful though, many people will annoy you later with friendlist requests Best to stick with your lower level clan members, and make a simple exchange, ie. I buff you, you give me part of drops(if they're leveling in Goblin Caves)
Also, you don't really need expensive equipment, since generally you're not fighting anything directly. So you save money on refines.
If you are *full* support, it will be miracle if you manage to kill someone at your level in PvP. With no combat spells, you are limited to physical attacks, which aren't really that great. If you have Fire Ring, your chances are sligthly better, but you simply do not do enough damage to defeat someone at your level. Blessing Armor and Cure/Heal make you very difficult to kill, but do not overestimate them. As a Cleric, you're always first target of opponents party - and in such cases you should carry potions with you, your spells will not be enough.
Also, be careful in Forgotten Temple, people like to use White Icings there to Silence you - thus making you unable to use skills for few seconds, which can be enough. Potions are a must in such cases, unless you run fast enough to avoid them - which can be tricky against Dex Up users.
However, if you *do* want to kill something, you would need at least few combat skills. Not neccesarily at high level, Power and Damage support can make lvl1 skill into level 5. Lvl1 Mana and Ice bolt are cheap, compared to amount of SP you get at higher levels and still do some damage. For maximum effect, switch to staff and use Staff Stun, this skill stuns surprisingly often and combined with lightning it can actually let you kill people - unless they're another Cleric that just heals himself - or someone who drinks potions like crazy.
In short, your basic tactic is : Cast Blessing Armor and use your offensive skills if you have them - if you don't, just keep healing and hope they get tired and leave you alone. Self healing Cleric is probably toughest class to kill(without Silence), giving your friends(you didn't go on CF alone, did you?) time to help. It is possible to outrun Soldiers and use hit&run to slowly wear them down with Wand attacks, but if you don't even have Fire Ring, it will take ages and if they get close to you, lack of stuns will kill you.
In temple, your summons can deal significant damage and actually let you get kills(especially if you have Summon Mastery lvl2 allowing you to summon 2 of them)
First of all - partying with strangers is usually waste of time. *Especially* if they're clanless strangers. In such case, they respond to no one for their behaviour and can be as nasty as they want. First sign is usually "anyone" item share setting. Such parties should be avoided at all cost - since Cleric buffs from distance, you won't be able to pick items before meeleers do that. In the end, you will use hundreds of OJs/CBs(crystal berries) and not gain anything.
If party sets items to orderly - make sure to tell them not to split up. That is another main problem with random people - they run off in all directions and expect you to heal them, ignoring the fact that you have to run through half of map to do so. There is also "quest monster" syndrome, where they break combat and run off to kill that Kaiman Warrior or whatever. In such case - ignore them and focus on main group. If you chase after them(assuming they are in trouble), not only you will not make it on time, you will also leave main group in danger. If they're smart, they will use meat or potions. If not - it's their fault.
Also, just because you heal people, it doesn't mean they can take on anything, *especially* if they decide not to use their own healing potions/meat. Taking on stronger monsters is fine, but there's limit to that. If you find yourself constantly using OJs just to keep party *barely* alive - look for easier area.
In general, it is best to party with clan. Be it your own, or just random clan. Unless that random clan has negative reputation. If you're clanless and do well, you might get invited - Clerics are in high demand in most clans. If it's your own clan - things are so much easier. You partied before, they know how to behave, they will(or at least should) share items when needed. That's what partying is all about.
Myself, I heal whenever ones HP drop below 75% - it's somewhat taxing on mana, but I can be sure they won't die unless something unexpected happens(i.e. Candle Ghost buffing all monsters in area) This is also important when people don't use meats - you can't wait for them to drop too low.
And if someone feels like he's being merciful by allowing you to join party and treats you like walking HP potion - leave.