Heres a little guide from a game i spent too much time playing...! So you want a hardcore level 19 rogue eh? Then simply follow this simple gear guide to attain arguably the best lvl 19 gear in the game.

Head: Lucky Fishing Hat = 15stamina
Head enchant: 8 agility (libram of voracity)

Neck: Scout's Medallion (H)    = 6agility / 2stamina
      Sentinel's Medallion (A) = 6agility / 2stamina

Cloak: Sentry Cloak = 4agility / 5stamina
Cloak enchant: +12 dodge rating

Chest: Blackened Defias Armor = 4str / 3agi / 11stam
Chest enchant: +100 health points

Wrist: Forest Leather Bracers = 5agility
Wrist enchant: +9 stamina

Hands: Scouting Gloves of the Money = 4stam / 4 agi
Hands enchant: +15agility

Waist: Deviate Scale Belt = 5agi / 6stam / 3spirit  - arguably since patch the defias belt is better.

Legs: Dark Leather Pants = 8agility
Legs enchant: +40 stamina / +12 agility

Feet: Nat Pagle's Extreme Anglin' Boots = 12 stamina
Feet enchant: +6 agility / Speed increase - i have 3 pairs, 1 has boars speed, 1 has this enchant and i have another pair with surefooted.

Ring 1: Meadow Ring of Eluding = +12 dodge rating / 1agi  - arguably since dodge nerf, these are not so powerful now, i still have 2, but am favouring a monkey 3/3 ring and the pvp ring.

Ring 2: Meadow Ring of Eluding = +12 dodge rating / 1agi

Trinket 1: Arena Grand Master = +12 dodge rating /
20secs shield absorbs 750-1250 damage , 30mins CoolDown

Trinket 2: Insignia of the Horde / Alliance

Weapon 1: Shadowfang = 29-55 damage , 17.8 dps , 2.7 speed
          +4-8 shadow dmg , Chance on hit to throw
          a shadowbolt that causes 30 shadow dmg.
Weapon 1 enchant: +15 agility  - lifestealing or crusader on main hand are viable, even possibly "better" alternatives depending on personal choice.

Weapon 2: Cruel Barb = 30-57 damage , 15.5 dps , 2.8 speed -
          +12 attack power.
Weapon 2 enchant: +15 agility

Extra items ...

Ring 3: Seal of Wryyn = 3str / 3agi / 4stam / 4int / 3spir(A)
        Seal of Sylvanas = 3str / 8stam (H)

Ring 4: Protector's Band = 4str / 4agi / 2stam (A)
        Legionnaire's Band = 4str / 4agi / 2stam (H)

Weapon 3: Assassin's Blade = 20-39 damage , 15.5 dps ,
          1.9 speed , 3strength / 4agility
Weapon 3 enchant: +15 agility

Trinket 3: Arena Grand Master = +12 dodge rating /
20secs shield absorbs 750-1250 damage , 30mins CoolDown

A great site to help with twinking your wow character is "the pwn depot"
There are also a few NEW twink aids, since patch. tradeskills can affect combat skills with crit for skinning, hp for mining etc. Personally i like the crit from skinning and the little self heal from alchemy. Try for yourself!

Good Luck in Azeroth!