K so this guide is meant to give you everything you need to know about twinking 20-29 for a rogue.
First i know there is another 20-29 twinking guide but its very outdated and lacks a few key things that people might like to know. (race benefits for that range, which items can get TBC enchants and one or two others)
*NOTE* ANYTHING WRITTEN IN YELLOW IS FOR ENGINNERS ONLY I highly suggest you go engineering if you are intent on making a good twink
First your race.
In my opinion the best choices are both horde
Undead: By far the best choice for a rogue in BG's through all the levels, cannabalize and will are just too powerful to pass up if you want a PvP rogue
Orc: stun resistance and blood fury are both very good the extra burst you can put on a Flag carrier.
Next choices for alliance would be either:
Dwarf: the racial stoneskin is invaluble against rogues and warriors for getting rid of bleeds and escaping also the non slowing makes it very helpful for getting away if carrying the flag
Gnomeyes sadly they are good :P) Escape artist is also extremly helpful as a second trinket to get away from the kiting hunter/mage. Also the engineering is a bonus seeing as you are going to be engineering if your a serious twink.
Next we have talent specs.
The best would have to be: Talent Calculator - World of Warcraft
You can swap the points in master of deception for more in assassination if you wish or you could put them in improved gouge, however it its probably not needed if you follow this guide to a T as your damage is that high. This talent spread is obviously for daggers.
http://www.wowhead.com/?talent=fZrxhd00x combat slow weapon heavy build (slow weapon as in sword/mace) your main damage is sinister strike and evis using riposte whenever it pops up. Due to the change in riposte is deemed a little less useful for 20-29 twinks but still gives nice damage and a bit of survivability from endurance (+4% stam reduced CD on sprint/evasion)
http://www.wowhead.com/?talent=fMxcMZhZcb This one is for the controlled dagger rogue, full stealth, improved gouge, cheap expose armour for improving your burst but keeping your DPS high through using it (15 energy for it is nothing with the thistle tea you can spam)
Next we have Gear:
Helm: Pathfinder Hat of the Tiger - Thottbot: World of Warcraft *note "that is the of the tiger" some may prefer the 90 health and take "of the monkey" They are the only two choices really, Also worth noting that the cats eye goggles are very helpful for finding that guarding rogue/druid on the flag carrier or flag spot and can be given the +100 hp enchant from librams
Neck: WSG neckpiece no questions
you can use River Pride Choker - Thottbot: World of Warcraft until you get the WSG one but it should be changed asap.
Shoulders: Mantle of Thieves - Thottbot: World of Warcraft mantle of thieves, you could also swap it for the forest tracker epaulets for a bit extra damage depending on your talent spec. Also worth noting are the Wintergrasp/emblem of valor rewards that are account specific, i Don't know the stats of them as i haven't seen a 20-29 set so sadly i cant link them if i notice someone who happens to link the leather stats then ill put their stats up for consideration (*NB* they cost 300 stone keeper's shards and 45 emblems if i remember correctly)
Back:Tiger trike mantle.
Parachute cloak is your best choice as it can be given TBC +12 agility enchant
Chest: Raptor hunters tunic from the stranglethorn raptor hunting quest, you wont be able to solo it but im sure you have a friend somewhere to help.
Bracers: Emissary Cuffs of the Monkey - Thottbot: World of Warcraft although the chances of you getting them are so slim its not even funny ( i never managed) so your next choice is Barbaric bracers, any leatherworker can make them so easy-peasy to get
Gloves: Razzeric's Racing Grips from the http://thottbot.com/q1189 quest obtainable at 29.
Belt: Deftkin Belt - Thottbot: World of Warcraft but only until you get your defiler's belt it is 100% your main choice and is extermly simple to get so no excuses
Legs: Petrolspill leggings or Ferine leggings are you No.1 choice ferine if you wish for the extra damage and petrol for the health.
Feet: Defiler's Leather boots, with Headhunter's Slippers of the Monkey - Thottbot: World of Warcraft until you get them
Rings: WSG ring and Thunderbrow ring, Thunderbrow is a BoE blue so AH is best bet id assume.
You can also farm for the epic ring from SM library off the last boss, but this is PURELY for E-Peen boosting it is not going to be better than the other two in normal circumstances (with lucky proc's it may help you flag carrying but this is unlikely)
Trinkets: AB talisman with PvP trinket is most likely your best choice. the Gurubashi trinket is very nice aswell if you want 12 chest wins in there (MUST be done on your twink)
Ranged: Naga Heartpiercer from Lady sarevessa in BFD with a +3 scope on it
Weapons:
Main hand dagger: Toxic revenger/Claw of the Shadowmancer (Toxic is off the elemental in gnome claw is BoE)
alot of people will suggest scout's blade or torturing poker but if your going my first talent spec your damage is that high with toxic and claw its possible to 2 or 3 shot most people apart from the stam stacked twinks (although you will still easily beat them with 1500 burst off ambush and backstab including white damage)
Main hand Slow weapon: Two choices here either Zealot's blade or Skullbreaker. Skullbreaker has a loss of damage but is allowed mongoose so it is a preference as to which you would prefer the static damage from Zealot's or the boost off mongoose (personal preference is the mongoose 120 agility is a lot at 20-29 as you can imagine)
Off-hand weapon: Scout's Blade for all concerned
Almost done don't worry
Enchants:
Helm: Libram to get +100 health
Back: +3 agility
+12 agility for parachute cloak
Chest: +150 health
Bracers: +9 stamina
Hands: +26 attack power
Legs: Clefthoof leg patch +40 stamina and +12 agility
Feet: +7 stamina
Weapons: Mongoose if you have Skullbreaker mace, crusader on everything else.
Finally a quick note on proffesions, i would suggest engineering, cooking (thistle tea cheaper to make it than to buy it off AH) and the most important proffesion First Aid, you can't be a serious twink without these 3 proffesions, or at least having engineering and First Aid.
If anyone feels i have missed anything please say, Guide was done basically as i said there is another guide up but its VERY outdated, and this is giving me a reference point for my 2nd rogue twink (new account)
Thanks to: Imbecill for pointing out my enchant misprint on the chest enchant (i did mean the +150 first time:P) and for the gloves i had forgotten about them myself my eyes have gone a bit blurry as has my brain ^_^