This builds are based on my experience in raiding and my playing style, i think all Priest talent trees are useful when raiding if handled correctly.
This build is from the holy tree, holy tree is the most used by a priest because they were meant to be healers, during the build i find the problem of choosing Circle of healing or adding the 2% of mana of Mental strength , i choose Mental strength because i don't usually heal multiple targets.
Holy Priest healing build
In this build you are meant to be a damage dealer and at the same time you help other spellcasters specially warlocks because of the life and mana regeneration you provide if you make a decent amount of spell damage.
Shadowpriest raiding build
The discipline tree is mostly made to give better buffs and has spells like power infusion and pain suppression when you are in a hard situation, i have used this tree mostly to heal and not using high amount of mana so i don't know how good it is for spell damage, after using 42 points in discipline i leave open 19 point to use in the holy or shadow tree depending of what role you want to take.
Dicipline Raiding build