[BAAAAAAAAW, Beat to the punch, What I went over in this is pretty much said already, but I took a while to type it up....so I'mma post it anyway. ;-; ]
Welcome to WoW and hunterdom, first off. :3
I'm curious as to what you mean by your pets 'fail' you, honestly. You're at a very low level where neither you or your pets have really grown very much yet nor have vary many abilities to manage. :3 In PvP it's not all up to your pet to win a fight for you. There is a vast many things to take into consideration during battlegrounds/Everyday PvP if that's the kind of realm you are on. You won't start seeing true pet potential until later on when you can spec his build a lot more then just...oh...3-4 talent points into his tree. That being said, there are some pets that could help mitigate some of the issues you might be having in a pvp situation:
Dogs/Crabs - 4 second stun/pin
Bats/Wasps - 2 second stun
Birds of Prey/Scorpids - 10 second disarm
Monkey - 4 second Disorient
Serpents/Raptors - 30 second Sunder Armor -Multi-stack debuff
Foxes/Tallstriders - 30 second reduced attack speed
Carrion Birds/Bears - 10 second damage output reduction
Spiders - 5 second pin
These are possible pets to help you gain the time you are possibly needing to get back out of the fray you might find yourself in. Remember, with a hunter DISTANCE IS EVERYTHING. We have a minimum range, if something gets too close to where we can't fire an arrow, then we are at a slight disadvantage. We are weak to melee classes and strong to those who cast spells. [For the most part this is accurate. I'm sure some PvP Veterans around here can tell you otherwise. ;3]
Now. There isn't really a whole lot you can do about Twinks if you are running into true Twinks if this a battleground scenario. Twinks are toons who have had their exp shut of at levels that end in nines in order to get the best gear possible for that level bracket. [I.E. 19, 29, 39....ect.] Battlegrounds are the only exception to Twinking as they cannot turn their XP of in such a case. [Last I heard. Twinks now have their own BG queues, oh the lamenting I heard over that fiasco.] So you could either be running into a few Twinks treading the line or possibly just some well geared up players. [Either those who run dungeons only to level who are decked in all blues or those running around in heirlooms.] It's ridiculously hard to fight those in heirlooms when you yourself are not.
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As far as PvE goes, it really depends on what you are doing. If you are leveling by yourself aka soloing with quests and adventures...it's best to have a "Tank"/Tenacity pet. These serve as you tankers to keep things off you while you sit back and do your dps thing. Having said that. There has been a LOT of changes since I played my original hunter and I'm finding this out the hard way leveling my second one on Nesingwary.
All I can say is: LEARN TO KITE. Your best bet is to stay at your maximum distance while letting your pet handle up with the up close and person. Don't be afraid to MOVE if you need to. At LEAST until you level up enough that your pet can handle tanking an add without loosing it's aggro. :3 It might take a while to build them up properly, but after they do most of your tank pets will never let you down!
When it comes down to running dungeons, each pet family has a different family ability. It's usually considered rude to have your tank pet out during dungeon runs. [I say usually, because not all hunters are smart enough not to spec them for tanking or turn off their aggro abilities.] It's a sure fire way to make any tank in your run very irritated at you, very quickly. Some tanks might even find it as an inssult/take it like you are saying you don't have faith that they'd be a good tank. Ferocity pets are usually preferred, but there are some hunters who can rock Cunning pets and do it well. Usually, Ferocity is your heavy dps hitters. They focus on dealing damage and most people will either direct you at wolves or cats for a nice ferocity pet to level with. I personally leveled with a raptor. Being as I am a Beast Master for life, I moved from raptors to devilsaurs when I got my talents up high enough. Just make sure you turn their growl off before you start a run!
If you see something you like, try it out and see how it fits for you.

Later on down the line, you'll find out that you are one of the best buff bringers in the game. Our pets bring many things to the table and we can ALWAYS manage to fill a buff if it's missing during raids. So it's nice to have a good spread of pets from all families if you are going to raid. If you end up a casual player like myself.....*cough* Well.......what can I say, I like shiny pets.
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Now, as for 'best talent build'....Well. I am what I am and I don't know how to run any other spec, but I'm not saying my spec is the best in the world. It is FOR ME. Choose whatever makes you comfortable. The better you learn your spec, the more you can rock it in every aspect it has to offer. Beast Mastery relies heavily on your pet to help you deal damage. Marksmen blast things away with little help from the pet itself, that spec seems more focused on the hunter and their abilities to put out massive dps alone. Survival relies on traps and other resources to stay on top of things to blast their foes away. So in my opinion, play what you are most comfortable with and your skills will grow with that spec in time. :3