W, A, S, and D are your mortal enemies
The keyboard is your enemy. Not the entire keyboard, naturally, but specifically the old movement keys are your enemy. They are slow, clumsy, and inelegant. You will occasionally hear an experienced PvP maven talk about using keys for strafing, but put that off until you've mastered the tool of the PvP player: the mouse.
Turning and moving your character with the mouse is faster. Your character whips left and right in real time with your mouse, instead of the slow-paced about-face you get with a keyboard turn.
More importantly, if you're controlling your character with your mouse, your other hand is free for keyboard commands. Mastering this mouse movement simultaneously with executing keyboard attacks will significantly increase your skill at the game.
Trust me, learn this style of control first. No fancy peripherals, special keyboards, or flashy light-up mouse will get you as far as giving up W, A, S, and D.
Unlearn your PvE mindset
There is an absolutely mind-blowing amount of math involved in the PvE game. Boss abilities, procs, rotations, and specs have all been boiled down to their most finite elements. You can easily find this information with simple Google searches; there is little mystery left in the PvE game.
Very little of that vast amount of knowledge applies to PvP. Your experience will change wildly depending on which battle you're fighting, what your team members do, and what your opponents do.
Strategies aren't completely unknowable, of course. But your abilities and specs are all different. For example, talents that boost your survivability or cut down on your opponent's toolbox are more favored in PvP than in PvE.
You'll have to experiment. If you find yourself dying way too quickly, you probably want more resilience and stamina on your gear. If you find yourself surviving epic encounters but being unable to kill the opponent, then you may want more damage stats.
Your rotation will become about what you can get off instead of executing an elegant rotation. You'll start hitting your big attacks during good "gib" moments instead of on a rotation, because you'll need capitalize on weakness more than doing a general, high-DPS rotation.
Know the landscape
Learn your environments. A great deal of what separates a great PvP player from the rest of the pack is the ability to capitalize on landscape.
You almost never want to be out in the open. You should strive to stay in cover, only peeking around the corner long enough to let loose your own damage. As soon as you've blown through a damage rotation, duck back behind the obstacle so that the enemy can't return fire.
Tactics like these probably sound silly when you're talking about a video game, but they absolutely matter. You can't DPS that which you cannot target.
Learn the other classes
One of the most effective strategies I've practiced over the years is leveling a character of every class. Of course, that's a bigger time investment now than it was years ago, but it's still a great idea.
Leveling and playing all of the classes will educate you about the fundamental mechanics of your enemies. You'll learn what different graphics mean about ability use. You'll learn their strengths and weaknesses.
Most importantly, you'll learn what really horks you off as that class. If something wrecks your day as a warrior, for example, you'll know to do exactly that to any warriors you later fight.
You notice I lead off promising that you would die a lot. I stand by that promise. If you're learning how to PvP, you're going to die a lot. But keep at it.
Try to pay attention to what kills you, though. Were you out in the open? Were you getting tag-teamed by greater numbers? Keep a little notebook and keep track of the circumstances of your deaths and losses.
Over time, you'll very quickly start to see patterns. When you've determined that you die in a certain situation more often that others, then the key comes to avoid that situation. If you're dying in a tunnel in Warsong Gulch because you got outnumbered, don't go back into the tunnel without some friends of your own.
But above all else, give up the keyboard turning. We'll talk more about advanced PvP techniques next week.
Visit the WoW Rookie Guide for links to everything you need to get started as a new player, from how to control your character and camera angles when you're just starting out, to learning how to tank, getting up to speed for heroics and even how to win Tol Barad.