I was recently looking around to see if its worth the money to dual spec my shammy into elemental (its not) and found this site for both priests and elemental shamans.  There seems to be quite a lot of good priest information on it.

http://bobturkey.wordpress.com/

Every time a discipline priest slots a gem with mp5 on it, a new death knight is born.

Every time a disc priest uses more than one purified gem, a rogue starts an arena team.

Every disc priest who uses a spirit trinket (one exception) has secured themselves a dossier and an active case at the Internal Affairs department at Discipline Central Oversight.

If you need mana, get more intellect. Or, for more modest mana boosts, use one of a few solid trinkets that will extend your mana pool more than you probably think. Use a single purified gem to activate your meta. Otherwise, do not justify using any blue-tinted gem with issues of regen or even socket bonuses.

I’m watching you.