So I made a moonkin dps guide and I'm tweaking it a bit, I'm also noticing the typos I made which makes me sad. This guide isn't the best, most comprehensive or properly proof written, but it has the info needed to be not suck at being a moonkin. This and the other two posts I made before will stay pretty much as is though this expansion. I'm making another post that address changes due to patches and such. The idea is to read part 1, 2 and 3 then check the update post for anything that has changed.
First is spec, your rotation depends on your spec, so there. The way you should spec depends on what class/specs you raid with and your gear to an extent.
Improved Faerie Fire is my enemy and depending on your raid comp something you may need to take. It gives your raid 3% or about 78.69 spell hit on targets you cast it on. If you have a shadow priest the talent is useless. If you don't have a shadow priest you may consider it based on your comp. I chose to drop it because I run with only two other casters who are both capped and it lowers my dps and ruins my spell rotation. If your group is caster heavy and and many aren't hit capped I would run with it until they get Naxx geared which will easily cap them.
Second you must spec around mana regen. There are four regen talents available to you. Listed in order of which is best highest is Omen of Clarity, Intensity, Dreamstate, and Moonglow. I always take moonglow because of where it sits in the balance talent tree, the other choices aren't better in my opinion. Clearcasting should be in any build as well. If your gear doesn't have much spirit I would go with dreamstate if you have a decent amount intensity is the way to go. You should spec for as little regen as you need.
Talents to avoid are anything past tier 3 in resto, anything in feral. The only talent in the balance tree that I would never take is genesis. You can check the breakdowns on my dps and see that you don't have five talent points to increase dot damage by 5%.
My build is 55/0/16, out of the five or six builds I have tried this by far my favorite. With any kind of mana battery I only had mana trouble on Gluth, if I had used my innervate on myself I would have been fine. Rather than break down every talent, if you wondering out there post a comment and I'll respond.