My First Priest - Tips?Follow

I lvl'd a priest to 60. Definetly spec shadow (with five points in the wand talent in discipline). Assuming you are going solo at least *some* of the time, get 5/5 spirit tap; blackout is not that helpful pve anyway. Wear +dmg/heaing and +shadow gear normally, but build up a set of +healing +spirit gear to wear when you instance. You will be able to solo-heal instances with relative ease until at least the upper fifties.

Oh and one more thing. If you don't know about the 'five second rule' you should. Basically you don't use your spirit to regen mana until five seconds after your last cast spell (during combat). So especially when healing, and to a lesser extent soloing and duo-grinding, try to burst cast then stop casting for a bit to regen mana.... wait for your tank to get hurt a lot, then use your max rank healing spell (not flash heal), then immediatly follow that up with a renew to maximize your time out of the "five second rule". Your wand really makes or breaks your soloing time in my opinion... so if you're going to be buying anything from the AH it should be a wand. Remember shadow dmg wands are going to especially be your friend because of your shadow weaving talent. Hit up Black fathom deep at lvl 27 to get this wand http://thottbot.com/i7001. Healing really doesn't get hard for awhile (when your PuG is a mess it doesn't really matter how good a healer you are).

anyway hope i was helpful.

Like epix said, your wand is probably the most important thing you'll need while soloing or even leveling with your friend. Wands don't run on mana, so you can use them without resetting the 5 second mana regeneration timer. Shadow word: pain is also very good. When taking down a mob i usually shield, mind blast, shadow word pain, mind flay, then wand.

As far as your build goes, shadow is best for leveling, as it lets you deal far more damage than holy or disc. builds would. Although it seems weak, mind flay is by far the most mana-efficient damage spell. I spent my talents this way (although I did have to respec at level 20. If you don't want to respec at 20, use the second list I provided):

5/5 wand specialization (disc. tree)
5/5 spirit tap

RESPEC

5/5 into spirit tap
2/2 shadow word: pain
3/5 shadow focus
1/1 mind flay
(then 5/5 into wand specialization)