Demo for raid utility during 25 man raids for the sp buff.
Destro for large hits and PvP
Aff is currently the highest dps build, and used for long boss fights and PvP as well.
It depends what you want to do. For PvP, I find a destro/demonology build best, but if raiding an affliction/demonology build is brilliant.
i know that the best build for leveling a warlock is definitely Demonology but not to sure on rotation :/
Like most questions in this category, there is no way to identify a single talent that makes or breaks a warlock. Simply play around with the talents, or ask an experienced warlock player advice on what talents to take should help you much more.
Yes.
For 3.3.3 destruction tree's are very easy you can check out my build i pull 8k DPS in ICC. See Talent Tree in Related Links 3/13/55 is the PvE Spec. The other talent tree is PvP destruction.
It depends on how you play, there are pvp builds for all 3 of them as well as raiding builds for all 3 of them. If you have a spec that you like you should go to a website that shows you the best rotation for that spec for raiding or pvp and which stats you should have and what stats you shouldn't have.
Envenom with the build that is in the related links
You get the spell Shadowburn by putting your talent points into the Destruction tree as a Warlock.
There is 3 talent tree's on every class and its free of your choice were you can put them. You get 1 point per level starting at level 10. You get a total of 70.
Depending on what the build is used for (raid trash, bosses, solo play), an Affliction build is probably the best all around. A Destruction build might be better for clearing trash in instances, but will use far more mana than Affliction. With Affliction, you also have the health returns from Soul Siphon and other talents.
Undead.
Her Talent is too build and experiment, to Tinker with technology.