A few basic things to know when playing a spriest...

ok so you just rolled that priest you've always wanted and boy, does he look shiny. Take it from me and learn right away what you need to do/get/avoid for higher levels (40+) before you get there. This ought to save you a good amount of gold and grief for that matter, not to mention countless re-invitations to instance groups and raids. I've never actually written a guide like this before so be gentle and I hope it helps/makes sense.

Hokay, step 1:
Decide early on what you want to do as a priest, ie. healing, dps or a hybrid of both.This will make distributing talent points much, much easier and it should save you gold as you probably wont have to respec as often.
This leads into the actual talent tree. Keep in mind that i have never met a good priest that has completely filled one "branch" of his/her talent tree...the key is to pick what you want to specialize in and put between 41 and 47 points in it that way the rest can go in an area that will improve you main specialty. Also, I have never met a successful priest that has chosen a disc. specialty. As a general rule, the disc branch should only be filled in to benefit either holy or shadow abilities.

End of Step 1...btw, ill be posting these in installments so if you have any questions feel free to ask me in game