Ok, so there are way to many nubsauce chaps out there. I aim to remedy this, these are some of the things i personally do to be an effective healer and team member.
Stats - Obviously you can not spawn chaplain at the very beginning so you will have to get decent at combat to a point to not be a burden for your team in the beginning. So those of you chaps that just start stacking intel primarily with out endurance/str your useless in the begining of the game, keep that in mind. I start off first level with 4 in endurance, next 4 in strength, and then depending on how fast monastary will be up inteligence and endurance pretty much from there on out(endurance is HUGE for every class)
Items - I save 300 right away to get the medium armor, then use about 300 gold for the 3 sets of mana pots and i donate the rest just about every life, the mana shrine stones you can get are a waste of money.(use persistant items if you have them to conserve mana pots)
Technique - technique is key, blocking is your bff dont be afraid to take a few hits here and there to distract from a lower hp player until you have time to heal them. Pay attention to who is slaying fools, and who is being slayed, of course concentrate your healing to the better players. Also when i heal i focus on my next heal no matter if i have an enemy after my soul, which i usually have tons of people on me. Just keep moving and use the hills/charge to your advantage, be un predictable in your movements.
Group heals - the group heal is probably the best healing spell you have, not because it heals 1 target for alot, but of course it heals multiple targets including yourself, but you do not need line of site in order to heal some one, around corners or over a hill. It also has a little longer range then the single target heal which can help with a closing in on a damaged team mate hit them with a group heal as soon as its in range, then single target heal as you get closer.
Resurections - Knowing when and who to res can be difficult at times because i would say 60% of the time when an average chap reses some one some one else dies by that res because they res'd instead of healed the unit beind damaged, this is acceptable if your resing some one that is way better, of course if you can get that res and keep both up you just are that much better
Shield of sol - Shield of sol is a very powerful spell because it can be used offensivly for distracting fire from spires so teamates can close distanace with out being shot, it heals you every hit, and it saves your ass when your getting wtfpwned.
It was requested by some that i post some tips on this, i didnt mean to write an entire novel, but if you read all of this, your that much better of a chaplain already