Professions
There are technically only two skills that affect player's pvp: First Aid, and Engineering 

 First Aid  First of all, if you don't have?First Aid?-skill, you can forget WoW gold about winning anyone in pvp Someone might WoW gold ask why that is, but here is the explanationWarlock does WoW gold now have two defensive  spells (fear and seduction), both give you up to 15 seconds free time to do what ever you wantAnd  I'll really suggest that you'll spend one of those moments by healing yourself with a bandageSo  having Maxed First Aid for your WoW gold level really helps to survive, and as a warlock, clock is ticking for  you, not to them First bandages (Linen & Wool) are not helping too much, but after getting WoW gold silk-ones, they just keep  getting exponentially better and betterSo when you hit level 40, use your saved mount WoW gold money to  get enough WoW gold mageweave, and go to your local Master First Aid to solve the quest for Artisan First  AidAfter you get rid of the WoW gold 225-skill cap, create Heavy Mage WoW gold weave bandages (at least for the  Horde the same person who teaches the 225 teaches the heavy mageweave bandages when you got  skill up to 230), to get your skill up to 260, and the person who gave you the Artisan-skill, now  teaches you the Runecloth bandage, for freeAnd when you got skill for 290 WoW gold, learn Heavy  Runecloth, again for freeThose are the things you WoW gold should be using in PVP after level 40Getting  2000 hit points WoW gold in 8 seconds, while your target is running in fear or is seduced, is niceBelieve me
Engineering
This is very, very expensive skill to learn, and if you are not willing to sacrifice hours and hours for  developing single skill, then this part is not for youHowever, having Engineering really helps This far I've realized that there are only a few really good devices for PVP purposes here, the good  tricks are mainly WoW gold in the Gnomish SchoolAlthough the Goblin-school got the better end game tricks  (Deathray is awesome in the midlevels, 35-50 but not as dominating at the late game)Note that  even you can create items in only one tree; you can USE items from both WoW gold schoolsBest items are:  Bombs & Grenades  Bombs areWoW gold  usually cheaper to make, and got bigger blast radius than the grenades, but for the  balancing the bombs must be placed on the ground (user can?t move while putting the bomb down),  while grenades can be thrown while moving The reasonWoW gold  why players are using WoW gold these is not only limited to a extra damage, but the warlocks  especially are looking for the disorient effectIn my opinion, the longer disorient the better bomb
The Big Ones are the WoW gold best for this purposeThanks for the 5 second disorient If you choose gnomish school and do not have access for The Big One, Big Iron WoW gold Bombs and  Thorium Grenades are probably the best bet For those who didn?t knew : Disorient is one of a kind stun effect, which keeps the target helpless  for X-amount secondsYou can Summon the Infernal on that period, or load the WoW gold Shadowbolt?
Cooldown : 2 mins(Bomb timer)
Gnomish Net-O-Matic
Way to root the targetNet-O-Matic is really good, as you really want 'em to stay still
In the WoW gold: Net-O-Matic roots the user
Cooldown : 10 mins (Activates the snare timer)
Gnomish Shrinkray
After using this, the melee oriented characters are not doing anything in 12 secondsWay much  better than it looks WoW gold. In the case of Malfunction: Shrinks the user (smaller targets are harder to pick with WoW gold mouse! And  WoW gold gives giant growth to the target, giving  8 str to himIn really rare cases this device goes really wild and shrinks everyone in the area of  effect, sometimes let's the user outside of the AoE.

Sources : Buy WoW Gold, WoW Gold Tips, WoW Gold Tricks