PvP gear is something both well established characters and people new to a realm can take advantage of.
But first heres the basics of how PvP works.
Your level defines what bracket you are in and what map(s) is available for you to fight on. It starts at 10-14 and continues in 5's (15-19, 20-24, etc). Fighting and killing someone gives you a few points and winning the match more. If your contributing to a fight (like healing someone) you share kill credit and you both get the points with someone else.
The Warsong (horde) and the Silverwing (Alliance) are your starting factions. Both have handy items you may want to snag when you can.
Level 18 you can get a weapon (70 honor) a ring, cloak, or necklace (20 honor). level 20 you can grab a trinket (20 honor).
The other factions have little toys as you level up, more than I can go into without making this a massive post, I do want to highlight one particular item.
The Arathi Basin factions sell boots starting at 28 that will inherently increase your run speed 'slightly - 8% same as the enchant. This leaves you free to slap any other enchant onto your boots and to enjoy the bonus speed, especially if your a class like warrior or priest who runs at one speed, ever.
An example: Highlander's Cloth Boots
So, considering the backets I suggest you go in towards the end of the level curve (13-14 for the beginning one for example). Do a few games. Get a bit of honor for gear. Have some fun with it. PvP gives decent exp so you will be picking up levels as you punch those evil bad guys in the face. But its fun with a goal, that blooms at level 60.
If you have heirlooms the gear I want you to aim for is your epic 60 pvp gear. The Head, Hands, Feet, Legs, and a weapon. The only one I dont reccomend are shamans cause their just messy. Thats 390 honor for the gear and 185 Bow / 290 (2-h) / 370 Sword and shield or two 1-h weapons. Now 680 honor may seem like a lot but if you tackle it as I said it will tickle in nice and steady till your 60 and decked out in massively powerful gear. If you don't have the shoulder and chest heirlooms they will put you back another 250 honor.
This will make going from 60-70 hugely simplified - you wont see better gear for several levels in most cases and you will look very fine in your awesome duds. 76ish you will start to fond bits of it being replaced and at 77 you should try to grab some Wrath of the Lich King greens. The Honor costs also increase on gear but there are a few items Id like to draw your attention to.
For Physical damage we have: Ranged Brutal Gladiator's Longbow (350 honor), Offhands like Brutal Gladiator's Quickblade (105 Honor), and mainhands Brutal Gladiator's Slicer (245 honor), and a shield Brutal Gladiator's Shield Wall (175 honor).
For caster candy there is; Brutal Gladiator's Battle Staff (350 honor) Brutal Gladiator's Spellblade or Brutal Gladiator's Gavel (245 honor), and a shield Brutal Gladiator's Barrier (175honor).
Im sure you get the idea, check out the full list of weapons here, shields here, and offhand items here.
At 75 you start seeing things that will be a bit better than what you have. But I suggest you stay pat with what you have unless its something you just happen across. When you should be looking forward to is level 77-79 Cataclysm expansion green items. A full suit of these babies will make you the most powerful think in Northrend, or close to it. The weapons shame all but the greatest Icecrown had to offer and even then eventually their replaced.
I hope this will help.