Guide: Priest - Holy & Discipline

Not copying and pasting. Read the guide below.
http://elitistjerks.com/f77/t54618-wotlk_healing_compendium_v3_1_here_there_theorycraft_dargons/

Basic stats to aim towards :

Rules of Thumb for Holy
Stack haste up to 12-14%. Think hard about whether you need more than that, given raid buffs and talents.
Pick up as much intellect as you can. It's always valuable.
Spellpower is always good.
11 spirit = 4 Mp5, ignoring spellpower gains entirely. Given spellpower gains, a 2:1 ratio is acceptable.

Crit is always valuable, although less so once you break 30% raid-buffed (diminishing returns on ilvl points spent).

Rough goals for the start of Ulduar.25 are to have 2800 spellpower, 26-28% crit, and 12% haste, along with ~ 500 Mp5 I5SR fully raid-buffed.

Rules of Thumb for Disc
Pick up haste up to ~ 11% (hard-cap). Absolutely do not stack more.
Spellpower is always good, especially since you don't have Spiritual Guidance scaling your levels.
Pick up as much intellect as possible.
11 spirit = 4 Mp5, with no spellpower gains.

Rough goals for the start of Ulduar.25 are to have 2500 spellpower, 35% crit, and 8% haste, along with ~ 500 Mp5 I5SR fully raid-buffed.