Gear

As a druid, you have 3 possible types of gear to seek out depending on your role in your team - being feral, you'd need gear like a rogue's with attack power and attack bonuses, balance lets you be a moonkin and be burst DPS as well as increasing spell critical and offensive caster, while restoration, the most common, is a mere healing equipment search. Worthy of note is the fact there's Arena and PvP armor for each type too so once you get deep into the PvPing you will be able to select your gear faster and so it gives you more benefits.

As Feral, it will be recommended you go in with Karazhan (or preferably above) gear as many arena players stack a lot of hitpoints and aren't taken down as easily by your attacks. A good weapon (like the one from Terestian Illhoof) is also recommended for this playstyle. Not many Feral druids are able to last past the 1700 or 1800 ratings, but dedication will see you through, it's all about how you play!

Balance and Restoration both rely more on spellcasting and should be good with equipment out of the level 70 instances as you gather up enough points to buy your epic equipment, yet are helped a lot too if you can obtain Karazhan gear.

Popular Talent Builds

All 3 talent builds are popular; in lower brackets you will see them equally, as you move higher up, Feral druids start to disappear unless they have good weaponry, and restoration or balance druids become more prominent.

It is uncommon to see people using Tree of Life as support during a match since there's a high possibility that higher matches have Warlocks in them, Banish will work against you so try to avoid being in Tree of Life form if there's one in the opposing team.

Moonkins, while hard to play and make effective, are good for burst DPS teams who want to kill someone quickly. The ability to Cyclone and then focus fire someone is highly valued in a 2v2 or a 3v3 matchup.

Tactics

The first thing you have to keep in mind is that you must use and abuse Cyclone as much as you can during a match. Since it is a baseline spell, you will be able to cast it regardless of spec, and it severely hinders the enemy's plan. Combined with the ability to stealth in catform before the match begins, Cyclone is a great opener and will almost assuredly grant an advantage to your team right off the bat. This spell is even deadlier if you refresh it randomly on the non-focused target during the Arena match!

Always stay within range of a healer or make sure you have enough time to cast a Heal over Time on you or your teammate(s), many druids are careless and overestimate their damage or healing and end up dead with a quick burst of extra damage from unexpected locations. If possible, keep Heals over Time on you and whoever the enemy is targetting!

Be prepared to cast Cyclone twice initially, since most will not want to give you the early advantage and break it with their PvP trinket. Once they use it once, it's gone for another two minutes!

Keep an eye out for enemies with low health, you have instant damage spells that add a DoT; use them should you see one of them fleeing to try and bandage or heal up.

If you're restoration and have Tree of Life, make sure you're not facing a warlock within the enemy; remember you turn into an elemental, which ends up letting said warlock put you out of commission with Banish for 10 seconds!

Stay tuned for more updates to this guide, remember, you will win some, you will lose some, but in the end, play to have fun!