I don't think there is so much a guide for NM PvE, but there are some pointers to follow.
1. You will find grouping easier than soloing. Wis will make you a better healer and your tank will stay alive and your party will be happy!
2. NM is like a practice mode for for HM. I really believe the game doesn't start til you hit HM. By the time you have gone through NM you will know what you want and don't want.
3. Use trade chat... "lvl xx heal priest LFG".
That will take you through NM with ease.