Post by Aldones
Discipline Arena Priests: What the Pros Are Doing by Paolo will give you all the info you need to know.
Post by ZoraLink
Rotations? No. No, no, no. If you get that mindset already, stop arena. Right now.
Arena is about reactions, prioritizing, and reacting to the other team's reactions to your reactions to their actions. (Whee.) You need to decide whether to be healing, mana burning, DPSing, or dispelling at all times. (Sometimes it's obvious, heal, other times you get a moment free and you have to decide) Other times you have to decide whether to charge and psychic scream. Or you may decide to keep your psychic scream for when you get attacked. There is no "set" way of doing arena.
With that said, glyphs and specs are both flexible.
Recommended major glyphs (Minors don't matter too much, unless you plan on rebuffing in the middle of the fight, then get Fortitude):
Glyph of Renew (If you like instant casts like me, this also needs to synergize with improved renew in the holy tree)
Glyph of PW:S (Highly recommended)
Glyph of Pain Suppression (For starting arena people with lower resilience. As you go higher, you can remove this for another, though I still keep mine just in case.)
Glyph of Penance (Another highly recommended glyph, it's expensive on my server however, so be prepared to cough up some gold for it unless you're a scribe/know some scribes)
Glyph of Inner Fire (An unknown gem for some people, the armor bonus really helps against the plate wearers. Which arena is dominated by. Unfortunately. So yes, highly recommended.)
Glyph of Dispel Magic (An eeeeehhhhhh glyph. It's handy but not recommended.)
Glyph of Smite (If you're an aggressive player/have a partner good at CC)
Specs:
I personally use:
http://www.wowhead.com/?talent#bxIbuIGiRcoffktfxzIt's primarily if you like instant casts and keep on the move. I do both so it works well for me.
If you like being beat up while constantly casting (And opening yourself up to interrupts...)
http://www.wowhead.com/?talent#bxIbuhMiRIsfsRtfxzEDIT: Curse thee, Aldones. :P