The best possible thing for you to do dude is get to lvl 29 and stop leveling. Go to BG's over and over and over until you reach rank 5, buy your Alliance Insignia, Seagent's Cape and Senior Seagent's Bracers. This shoudl also get you to friendly with WSG so you can get the damage absorbing trinket. All extremely fecking useful in PVP.
Translations:
Battlegrounds are grouped like this:
10-19
20-29
30-39
40-49
50-59
60
Meaning if your level 29 you slaughter others cause they find it hard to hit you and you crit them very often.
Rank 5 is Senior Seagent. At rank 1 you get a tabard (Woo), rank 2 the insignia of the alliance. this is a trinket that instantly dispells polymorph (sheep), Charm (Succubus) and something. So a mage sheeps you, you click the trinket, you own their face. Rank 3 is Seagent and you get the high stamina cape along with a 10% reduction on the cost of everything from your alliance faction vendors, including your mount at lvl 40. its a stackign 10% on your honoured 10% discount so its 20% instead of 10% - 10%. Rank 4 gets you a high stamina neck piece and rank 5 gets you a high stamina bracer set.
Stamina is the key to PVP. If you can stay alive long neough to kill them, your life was pointless. And for a rogue having no HP isn't an option. You have to stay alive long enough to destroy someone, run and restealth.
Then on all your other armour you can wear monkey (Agility stamina) or high agility blue pieces (At lvl 29 with friends you should have the quest to kill the last boss of GNomeregan giving you massive agility leggings. These will last you a very long time). You should already have the Westfall Tunic from the quest in the Deadmines.
When you win in WSG (Warsong Gulph, a PVP battleground instance) you get rep (reputation). If you reach frienly you can buy a trinket off them that when activated absorbs X amount of physical damage. You can drag trinkets onto your tool bars for easy clicking.
As for rogues in PVP, i hate it. BUT, thats because i like team work and that is rarely found in rogues. Rogues go in, destroy someone, run out. Rinse repeat. Whats better than a rogue doing that? Two rogues doing it.
Definately not the best PVP class cause i will always say that is Warrior/Warlock but you can have some real fun as a rogue, that not alot of other classes can share. A funny one is doing a /giggle at someone right before you Ambush crit them for 1.8k damage when they are on 10% hp. But i'm not bastardy enough to be a rogue, i'm too honorable if you know what i mean.
Definately the most "leet" class in the game. I think you will enjoy it

Rogues can do things no other class can do, cheat their quests by stealthing their way through.
Errr i talk to much, i'll be quiet nows. Bye!