PvP Basics in World of Warcraft
A Whole Other Game
If you want to specialize in PvP, your character creation choices and talent specs should reflect that choice. In general, the more unique a class is, the more that class is favored for PvP action. This is not to say that hybrid classes (i.e. classes that combine the abilities of two or more classes) like druids, shamans, and paladins can't hold their own in the mill of murder, just that playing hybrids in a PvP setting requires a little more emphasis on working as part of a team.
Here are some general hints on playing hardcore PvP. Note that some of these hints apply only to playing on a dedicated PvP server (see below) but most can be applied to playing PvP on normal servers as well.
Win the battle before it starts - With the exception of Rogues, Warlock pets, and players laying an ambush you can see most threats coming. Knowing when (and where) to run is more than half the battle.
There's safety in numbers. When travelling, round up a crew of faction friends despite their levels (typing /anon will hide your level from other players) and stick together.
Stay out of the open, stay on the move, and stay alert; especially when you're fighting NPC mobs.
Casters and hunters need line of sight to execute their most powerful attacks. Grab some cover whenever possible, but don't get yourself backed into a corner.
Do what you do best, but do it big & fast - If you're specialty is damage, set up your talents to do lots of damage quickly (casters should concentrate on direct damage spells rather than damage over time spells, for example). If you're a healer, heal big and buff big; worry less about mana consumption than being able to heal a few players fast and give them a better chance to resist mind-control spells.
Most battles are less about winning than making your opponent lose. For example, snare a hunter's pet and close on him or her fast to minimize the hunter's ranged attack advantage. Silence/stifle/pummel a warlock so that they can't DoT and fear you. Root or snare a warrior to stay clear of their powerful melee attacks. Find a way to survive a rogue's initial barrage, mark them, and you should be in good shape to turn the tables.
Player vs. Player servers are for a special kind of gamer. While nothing matches the satifaction you get from beating a tough human opponent, similarly nothing quite matches the depths of frustration you'll sink to if you meet up with players who've turned griefing into an art form (in the name of PvP, of course).
Here are some classic PvP terms that you should be familiar with. If you feel a twinge of excitement from reading these definitions, you might find a home on a PvP server. If you feel a tinge of disgust, my advice: stick to the normal servers.
Ganking - Most commonly, this means sneaking up on a player engaged in PvE (Player vs. Environment) combat, and attacking them when they're at their weakest. Not the most gracious form of combat, but all's fair in war.
Zerging - Rolling through a lower-level contested zone with an army of higher-level players, or simply beating a player with numbers and/or level. Relatively safe (with PvP, there's always safety in numbers) and fun if you can get a bunch of like-minded people together.
Corpse-camping - Waiting around and attacking players as they attempt to retrieve their corpse. Regarded as one of the most despicable acts of all in World of Warcraft, there's really no defense except to outwait your opponent. Remember, they're probably as bored as you are and have less to gain by waiting around. Sometimes you might corpse camp to send a message, but let your ego subside; let them get up and flee at some point.
Assisting or Target-Calling- Well-organized PvP groups and raid groups stay alive longer, so you should always have one player that the group "assists". This player calls targets for the rest of the group to focus on, so that targets are taken down as quickly as possible. While this is a strategy for both PvE and PvP, it's worth mentioning here since a group fighting multiple player-targets is going to be a complete wipe in no time.