My wife recently won a Facebook contest run by those Razer guys to win a Sphex "gaming grade desktop skin", which is actually just a fancy name for a mousepad. That was great timing, too, because she'd been confined to using a ratty Manila envelope as her mouse surface for the past couple of months. She'd been able to raid just fine (apparently Manila paper works better than some conventional mousepads), although a new mousepad might help.
Once you've gotten your mouse, you'll want to pair it off with a proper gaming surface. My wife, who doesn't PvP, uses a generic two button optical mouse which she bought simply "because it's pink". She did drool at SteelSeries' Iron Lady gear (also colored pink), but all the fancy tech and extra dollars would be lost on her. On the other hand, if you've splurged on a mouse for your PvP, make sure to get a mousepad that at least takes care of your mouse. At its most basic, a mousepad is easier to clean and keep clean than, say, your desk.
Some gaming surfaces cater to specific types of play styles, such as rougher surfaces for more control or smoother surfaces for speed. Some are bigger for low sensitivity gamers who make long, sweeping motions, while others are smaller for portability and a gracious footprint. Find something that suits your play style. It's not something you have to invest in - heck, use Manila paper if you want - but the key is that it should complement the way you play. A good surface will also extend your mouse's lifespan.
You can invest in something that plain just looks good, such as Steelseries' World of Warcraft-themed mousepads or something simpler. As long as your cursor isn't jumping around, you should be good. Mousepads cost anywhere from free to wallet-burning (that 5C mousepad pictured above will crit you for $39.99). Also important, consider a wrist rest that will help prevent you from acquiring Repetitive Strain Injury. Low-sensitivity gamers who use sweeping motions won't make much use of a wrist rest, but it helps during idle time. Most any cushioned object will work.
Laptop users can make do with their machines' built-in keyboards while desktop users have an excuse to spend even more money. Serious gamers can be very exacting with their keyboards, as this is what will wear out rather quickly with intensive gameplay. Needless to say, as with all your gaming peripherals, choose something that feels good to your touch. Some players actually prefer the feel of laptop keys, as they're flatter and feel more responsive, with lower actual physical actuation time, and there are keyboards that replicate this or feel close to it.
Some keyboards offer a high level of customizability, such as the $199.99 Logitech G19 gaming keyboard, which has twelve keys that can be programmed with up to three macros. It can also take up to five keys pressed at the same time for incredibly complex macros or instructions. The $99 Razer Tarantula has ten programmable hotkeys and can take up to ten simultaneous keystrokes. Conventional keyboards choke, or ghost, at four or more keys. The $49.99 Steelseries ZBoard is a modular keyboard frame that can adapt to various games, including the World of Warcraft. Popping a $14.99 World of Warcraft keyset (currently available in the Wrath flavor, shown above, it was also available in vanilla and Burning Crusade editions) grants dedicated keys for frequently used commands such as roll, duel, or invite. There are dedicated keys for PvE and, important to this series of posts, PvP.
Here's one important thing to remember before splurging on a specialized gaming keyboard: just as with mice, World of Warcraft isn't incredibly demanding on keyboards, either. The game is robust enough to register a wide array of commands and macros using a conventional keyboard. This means that any ordinary keyboard can be tailored for complex gameplay using either the built-in Key Bindings and Macros feature or with the help of AddOns like Bartender.
Does this mean specialized keyboards are a waste of money? Not necessarily. Keyboards from reputable manufacturers should be more durable and designed to take a pounding. While most PvP gameplay has limited actions owing to the GCD, what's important is the register of a command when a button is pressed. For exacting gamers, those response times are critical. Assuming you have equal latency (another factor in PvP), whichever player gets his command register faster gets the upper hand. In fact, some keyboards boast a 1ms response time. It's minute, and over the Internet it probably wouldn't even matter, but if it gives you a psychological edge, why not?
In the final tally, gaming keyboards are a luxury, more so than a mouse despite the fact that most commands are executed through keystrokes. The Global Cooldown ensures that a player who times his keystrokes well - perhaps with the help of Quartz latency AddOn - will probably do even better than another who just mashes keys. As long as your keyboard registers commands properly, you're good.
A note on gaming pads
Some gamers prefer to use gaming pads, allowing for minimal hand movement and easy accessibility of important gaming commands. Many specialized gaming pads are suitable for MMORPG play - even retired blogger Phaelia is a fan of the Belkin N52te - and if you're a keyboard turner (which isn't ideal but perfectly alright, especially if you don't PvP), this will prevent wear on the keys of your regular keyboard.
As with Phaelia, I use the Nostromo because it helps preserve my laptop's keyboard from excessive wear. Such dedicated gaming pads usually allow customizable macros, multiple user profiles, different key states (thereby allowing more keys than what's physically available, usually ten to fifteen). It's a luxury and an idiosyncrasy - not necessary but allows me to be more comfortable with my gameplay. It offers many of the same features as other specialized gaming keyboards but greatly protects your wrist as it will remain almost always in a "rest state". Tomorrow, in the conclusion of this series, we'll have a look at your options for sound systems.
Previously on gearing up for PvP: