Started a Cleric, any tips?

[Jimjam]

Some of your hp/ac line of buffs can be used as heals.

Worth mentioning a second time, don't be afraid to use spells other than heal. Rooting a mobs to control who they hit will save a lot of mana in the long term. A well timed stun can drastically changed a fight.

Let melees do a little bit of your job for you; in med breaks someone will often offer to bandage the group to 50% hp, you might as well let them since no pulls will be coming in and it will result in the med break finishing earlier.