Hunter Arena Guides
As with every other class, get your insignia as fast as you can so you can dispel movement impairing abilities and hopefully get a damage increasing trinket to get your burst damage up should you need it during a battle. Other than that, it's largely up to you!
Popular Talent Builds
Hunters have the most variety when it comes to popular talent builds within the Arena, if you're only doing 2v2, Beast Mastery will be the best option to go with since your pet gains a good damage boost and you're able to take someone down fast. However, if you take a look at high ranked 3v3 or 5v5, you will notice Marksmans are more predominant. If you're able to stay behind and avoid being targetted by the opposing team, Marksman will do a lot better damage wise and you don't rely on Bestial Wrath to get the job done.
All in all, you can't go wrong with any certain talent spec, though it is recommended by some you get an improved sting from Mark so you can annoy cleansers with this and your pet.
If you're a NightElf, a popular ambush is to Shadowmeld as soon as you're ready and wait for the enemy to come scouting for you, you can then send your pet and begin attacking by surprise, giving you a few shots in without them seeing you.
If you bring a scorpid pet, you can sic it on someone and have it do its poison attack, coupled with your stings, it will be hell for enemy cleansers to keep themselves and others alive with their mana reserve intact!
Always focus on one target but don't be afraid to move out of line of sight of the enemy, a Hunter can always pop a few shots in and retreat, effectively "kiting" people or disrupting their initial strategy by getting a few hits in.
While direct burst damage is good, try to keep traps around and your pet ontop of a healer or caster, which should be your first targets. Cast interruption and general annoyment are great during an Arena match.
Don't forget you can bandage! you can always run away and bandage up if you've received too much damage up front.