Heya
Welcome to the forums, Aeonix. Novel inc!
First thing I'd suggest, actually, is grabbing this addon, if you don't already have it:
http://wow.curse.com/downloads/wow-addo ... s/spy.aspx
It's called Spy, and like others like it (Stalker and Paranoia, for example), it tells you as soon as an enemy player's picked up on combat logs and gives you a neat little display. It'll tell you the name, level, class and clicking the name will target them (when out of combat) assuming they aren't stealthed. This means that if a rogue or druid stealths, you'll know it, and possibly be better prepared. If you take the Stalker addon instead (also found at curse.com), it will also tell you the enemy's last action (i.e. Overkill or Master of Subtlety when a rogue stealths, or Prowl for a druid's stealth) and keep a list of kills vs deaths for each player.
Second, if you're going to be shooting some mobs, I'd leave a freezing trap under you on every cd. I can't tell you how many times something's Pounced or Cheap Shotted directly into a trap, and if you see your trap get disarmed you know it's time to recall pet. Feigning Death to make them lose target should give you time to set your pet on them and either Disengage or Wing Clip and strafe away. Randomly throwing flares about will put those stealthies on edge too--assuming you have flare at 65? I can't remember
Onto the topic at hand, pets--most have already been covered, but here's my personal take.
If you're levelling with a Tenacity pet, then as people said Crocolisks with their snare would be a good bet. Crabs still have a channeled root, too.
For Cunning, a Bird of Prey isn't a bad choice due to the disarm, though it won't help vs ferals. A Bat for the stun may be better (and the stun costs no focus--Bats are underrated imo), and ofc Spiders for the root are great. Once you can get Exotics, Silithids or Chimaeras are both amazing for kiting--and the Silithid gives an HP bonus to boot. (I actually prefer Chimaeras--once they get going, they can keep even a Paladin with Crusader Aura from escaping.)
For Ferocity, consider a Dog. The new root from them is quite good. It's the same thing a Crab gives, but they'll put out a good deal more damage than a crab will, allowing you to focus on kiting your enemy. Once you can get exotics, Spirit Beasts are, of course, amazing with their heal. Spirit Beasts are currently my go-to WPvP pet.
The talents you give them are important too; if you can get Intervene, Charge and Roar of Sacrifice on your Tenacity pet, Bullheaded and Mobility on your Cunning pet, or Bloodthirsty, Charge, Heart of the Phoenix and Lick Your Wounds on your Ferocity pet, you'll already have a pretty good advantage (and obviously Dash or Dive on every pet that can get it!).
If you're getting ganked while fighting mobs, hit Escape as soon as you are hit, so the enemy player's next hit makes you auto-target them, then send pet. If your pet's on passive, he'll ignore the mob and go straight to the player (I find that they're buggy recently when left on Defensive, although that's how I prefer them). If you get sapped while mounted, dismount (you can do this while sapped) so that your pet has a chance to defend you when the opener comes. If you know a rogue or druid's nearby, try to move away from mobs a bit and "sit down to drink," putting the pet on Aggressive; hopefully the pet will find it before it attacks.
Hopefully some of this is helpful to you, and here's hoping the jerks stop attacking!
I have a 65 belf on a pvp realm and it gets tiring having everyone kill me while my pet bites their ankles (this is assuming they don't do as below). I listed my pets in my profile, maybe I have a good one now and just don't have the talents set properly. 
