Post by Slipshadow
Haste/Spirit > Crit > Mastery
Plate Haste/Spirit > Plate Crit/Spirit (Reforge Crit -> Haste) > Plate Haste/Crit (Reforge Crit -> Spirit) > Non-Plate Haste/Spirit > Anything else.
You don't want a single piece of gear with mastery on it equipped, if you can avoid it. The reason for this isn't because Mastery is terrible, although Mastery isn't very potent for Holy Paladins. The reason Mastery ranks so poorly is because you have to sacrifice much, much better stats. Some mastery is better than none, however, so it is beneficial to equip plate.
The only thing that breaks the above ranking is an abundance of Intellect. If a piece of gear has 40+ more Intellect on it than a currently equipped piece, you want it. Intellect is, by far, the most important statistic for a Holy Paladin.
If you want to get into the specifics of weighting... I typically rank things as follows:
Critical Strike: 60
However, those are my completely arbitrary rankings. No mathematics to back the values.Gems
Every Gem should have intellect.Brilliant Inferno RubyPurified DemonseyeReckless Ember TopazTalents & Glyphshttp://www.wowhead.com/talent#scIbzrduufzhbZc:caVrfsMzc
You can change the glyphs around a good bit, but I think those are the best "starter" glyphs. You could easily pick up Divine Favor, Light of Dawn, or Lay on Hands glyphs and be more effective once you're comfortable.
You definitely want to pick up Crusade from the Retribution tree. It's a 30% increase to Holy Shock healing, and after you kill an enemy your Holy Light heals for as much (and more) than a Divine Light.