All Druids have a reason to hit the battlegrounds even if they don't actually like PvP. Many ferals go because +resilience gear is a means of achieving crit immunity while tanking, which is a significant problem that worsens as your guild progresses through raid content (it is an enduring irony of feral life today that the Druid spec that needs PvP gear the most is by far the worst suited to it). Many Moonkin PvP because leather with +spell damage is still difficult and/or time-consuming to get, despite significantly better itemization of late. Restos PvP because healers are very valuable in battlegrounds, and a geared and skilled Resto Druid is worth his weight in arena charter gold.
There is, however, the minor matter of getting geared and skilled. If you're earning honor for Season 1 and Vindicator's, this is what I've learned in my quest to become something other than dog meat:
PvP as a Druid is designed around attrition and mobility, and you forget either of these at your peril.
A great deal of Druid success in PvP, more particularly as a balance or resto, hinges on your ability not to be caught (this is also the source of much popular anger at resto success in 2's arena). We are designed to run away in no small part because our options as a healer once caught are very limited -- and if you are healing, you WILL be targeted early. Paladins wear plate and can Divine Shield; Shamans wear mail and can Earthbind/Frost Shock; Priests can Psychic Scream/Mind Control, will have Inner Fire up and may in fact be packing more armor in caster than you are, and Discipline Priests will have Pain Suppression. Additionally, shapeshifting is a mana-guzzling obligation that these three classes obviously don't have to worry about. And I won't sugarcoat it; when you're starting PvP as a Druid, once you are caught it is very likely you will die -- so don't get caught!
A Druid's options in close combat are generally limited to abilities that will allow them to keep running. Defensively, Bear Form is fine for a quick Bash and a run, but as a resto or a moonkin, it affords you vastly less protection than it does a feral. If you have Feral Charge, and I certainly hope you do, you should be using the skill offensively as an interrupt and defensively as a means to get away from a melee opponent. If somebody's beating on you, Bashing them is actually a poor choice unless they're the only person in range. Target one of their caster buddies, Feral Charge them, Bash if you have it up, and shift to Travel Form immediately for a quick getaway. By the time your opponents have recovered then you should have sufficient distance on both to find help or, failing that, a safer place to heal.
ATTRITION: Assuming equivalent gear, even a feral or a moonkin is unlikely to outdamage a pure DPS class in a 1-on-1 match, and a resto NEVER will; that is, after all, the strength of a pure DPS class. This is entirely immaterial if you can OUTLAST them, and that is precisely what a Druid is designed to do. Restos will learn this quickly, but it can't be overstressed for ferals and moonkin; heal early, heal often, and never let your health hit 20% or less if you're within spitting distance of a warrior who can Execute you. Ferals have bleeds, moonkin have Moonfire and Insect Swarm, and depending on their build, restos may have both as well. Bleed them or DoT them, Root them or Cyclone them if you get into trouble (or even if you don't), get out of range, and heal if you have to.
Note: use Rank 1 Entangling Roots. The damage done by Roots is negligible anyway, and there's no point using a higher rank because no CC effect in PvP lasts beyond 10 seconds. This will save you a lot of mana, especially if you're feral and operating with a smaller mana pool anyway.
A special note concerning rogues: always try to slap a bleed on them if you can. They can Cloak of Shadows out of magic effects (on a 1-minute cooldown) but can't out of bleeds. The quickest thing to put on them is probably Rake or Lacerate if you're a resto or moonkin, and the energy or rage that these require is an additional reason to go 5/5 Furor. This is worth doing if their attention is elsewhere; you're not as likely to pull it off if their attention turns to stunlocking you instead. Of course, if you know they just blew CLoS, Faerie Fire does not go amiss and will prevent them from Vanishing until CLoS comes up again.
Concerning both Rogues and Hunters: keep Abolish Poison up and running as much as you can. It's relatively inexpensive and will keep all manner of debuffs off you, most notably the very ugly Viper Sting.
MOBILITY: Short of a Shaman who has fully talented Improved Ghost Wolf or a Rogue who blows his Sprint cooldown, you have the capacity to be the fastest player on the Battleground. If the match-up between you and an enemy goes south, or the enemy gains reinforcements, run like hell.
Travel Form a safe distance away, Rejuvenation and Lifebloom should go up, then -- depending on your proximity to danger and/or DoT's still ticking on you-- either Travel Form again or Cat Form. Why kitty? As soon as you get out of combat and aren't taking any DoT/bleed damage, re-stealth (or Shadowmeld if you're a Night Elf, which carries the additional benefit of being able to eat/drink while stealthed).
Barkskin: the old "That %^@&* Warlock killed me after I killed him!" is no less true now than it was back in vanilla WoW. If you're full of DoT's from a lock or a shadow Priest (or anything else, for that matter) and you have to exit stage left, pop Barkskin before you take off as it may allow you just long enough to get a heal off. The same is true while being stunlocked or fearlocked and taking heavy damage; you CAN use this while otherwise incapacitated.
And on the subject of other players' cooldowns: Great! Hit the road while the Shaman spends the duration of his Bloodlust trying to find you again and the Hunter tries to get in range to make sure that Bestial Wrath didn't go to waste. I can't stress this enough; the more time you spend in motion attempting to outrange an opponent's abilities, the less time you'll spend trying to heal up a Chain Lightning/Aimed Shot/Pyroblast.
KEEP MOVING! At lower levels of gear you should be playing conservatively. The classic resto dilemma is what to do when you're running alongside a flag-carrier as the healer and you are being focus-fired. Do you split? Or stick with the FC? The problem is rarely as dire as it appears unless the flag-carrier is badly geared (in which case, why are they carrying flags?). Every enemy on you is one who's not giving their full attention to an FC, and your DPS should not allow you to be focus-fired without riddling the opposition with a world of hurt (if they do, well...this is one of the reasons that so few people heal in BG's, and it's not your fault if you don't get the support you need). HoT the FC, HoT yourself, Bear form and charge a caster, War Stomp if you're a Tauren, Cyclone one of their healers (who is very unlikely to have you targeted), Root one of their melee, and kite whatever else is still alive. This is where gear plays a role (you just have to have enough resilience to pull this off, but the set available at Honored reputation with Outland factions -- more on this below -- is sufficient), but if you can do even a few of these, you'll cause enough chaos and confusion to split the attacking party. Doing this also makes it easier for your own DPS to mow down targets.
In the above scenario, please note that it is not even necessary to survive the ordeal if you're focused on the battleground's objectives. If you end up in the graveyard, but the flag-carrier ends up on the node because you broke the opposing team's offense, you did your job and you did it well.
SPEC: In general it is very tough to argue that you will make more of a difference to your battlegrounds as another DPS, unless you're a feral in good gear who plans to tank NPC's in AV or run flags in WSG/EOTS. If you're just looking to bank honor and tokens, I would advise going to battlegrounds as a PvP-specced resto. Not only does this afford the best survivability independent of gear (an important point to consider if you're just wading into PvP), but it also affords you the opportunity to practice the spec that you will most likely be using in arena unless you're one of those hardy souls PvPing as a moonkin or feral (and God bless you if you are).
While feral I PvP on my PvE spec, 0/47/14, which isn't amazing for PvP but will get the aforementioned jobs accomplished. Ferals and moonkins are welcome to write in with suggestions for better specs to utilize for more hardcore PvPers: for my part, I respec to one of the following resto builds if I'm farming honor:
8/11/42 is the traditional PvP resto spec and affords maximum healing power to HoT's, plus Feral Charge, Thick Hide, 4/4 Improved Nature's Grasp, and more importantly, 3/3 Control of Nature to allow uninterrupted casting time on Entangling Roots and Cyclone.
11/11/39 is another option and frankly one that I like better. It is a more offensively-oriented version of 8/11/42, with points taken from Empowered Rejuvenation (which, don't get me wrong, hurts a lot) and put into the balance tree for Improved Moonfire and more importantly Insect Swarm. Insect Swarm is a highly mana-efficient DoT (in fact, the most mana efficient DoT in the game) that additionally decreases the target's chance to hit by 2% (Remember! The life you save might be your own!); Moonfire is HORRIBLY mana inefficient if you're spamming it (and you shouldn't be), but becomes a decently-efficient DoT if re-applied as necessary.
As a Gladiator-ranked Druid on my own realm observed, the beauty of the 11/11/39 spec is that it will allow you to solo Mage/Warlock/Hunter pets if necessary, and will also encourage you to play more aggressively once you have better gear. If you're just starting to accrue honor in battlegrounds, 8/11/42 is the better option as you will have to play more defensively anyway, but do consider 11/11/39 for arena.
GEAR: There is no amount of skill or strategy that will save your furry butt in greens from an MS Warrior in full Season 3. There, I said it. Stop feeling guilty if you get two-shot by one of them in your PvE gear while you're saving for Season 1. In raiding we say that it is burst damage that is most likely to kill a tank, and the same principle applies in PvP, which is the reason for the existence of Resilience.
Resilience does not make you more likely to triumph over an opponent. What resilience does is it gives you time; time to react, time to heal, time to CC, and time to get away, simply because you are significantly reducing incoming damage. Resilience also dovetails into Druid-style healing very well, by reducing damage to a more manageable and predictable flow that HoT's cushion well. This is why Druids are a terrible choice to heal undergeared players but one of the best possible partners for a geared one in 2's.
With the introduction of buyable Battlegear sets available at Honored reputation with 5 Outland factions, there's no real excuse for stepping into battlegrounds without the Resilience you'd at least get from a full set. As a moonkin or resto Druid, you can also use the old trick of swapping in two pieces of Kodohide/Wyrmhide for an extra +35 Resilience from the two-piece bonus (yes, it stacks!). You should also be able to manage Seal of the Exorcist or Band of the Exorcist from Spirit Shards in Auchindoun, and make sure you gem and, if fiscally possible, enchant these puppies. You will probably want to save your gold for expensive enchants and gems once you get the honor for Season 1 (or, in the next arena season, Season 2), but make sure you drop the money to gem and enchant Vindicator's gear like it deserves.
Will the gear enable you to go toe-to-toe with opponents in full Season 3? No. But you'll live a lot longer than that buddy of yours in PvE gear who spends half his matches waiting to rez, and when it comes to PvP, what is ultimately important is not your ability to crush but your ability to outlive.
All the world will be your enemy, Prince with a Thousand Enemies, and whenever they catch you, they will kill you. But first they must catch you, digger, listener, runner, prince with the swift warning. Be cunning and full of tricks and your people shall never be destroyed.
-- Richard Adams, Watership Down
(The beauty of stealing other peoples' columns is that they have no control over what you decide to quote)