Priests

Here's the talent guide for the Priest class.

Discipline is the priests optimal PvP spec, you gain survivability, and keeping others alive as well.
Casting Penance, Renew, and Flash Heals as needed.

http://talent.mmo-champion.com/?priest=150320313050251233132303125123050100000000000000000000000000000000000000000000000&glyph=051215030602&version=9637

Who said Priests only heal? Shadow Priests can be a great raid aspect with replenishment effects. A good rotation is Vampiric Embrace, Vampiric Touch, Shadow Word: Pain, Devouring Plague, Mind Blast, and Mind Flay. When the target is below 35% health, feel free to cast Shadow Word: Death, but be careful to watch your health.

http://talent.mmo-champion.com/?priest=050320300000000000000000000000000000000000000000000000325323051013012323150301351&glyph=171819030602&version=9637

For Holy, refer to the healer post.
Enjoy.