There is definitely going to be more, I just don't have much time at the moment. Also, please post which guide you used if you used one of these so I can see which are the best/most popular.
Druid
Hunter
[Guide] 29 Twink Hunter by Amedis
(http://www.mmowned.com/forums/wow-gu...nk-hunter.html)
Proper 19 Hunter Gear Guide ! by cruorem
(http://www.mmowned.com/forums/wow-gu...ear-guide.html)
MOST BALANCED 29 hunter twink build by morica
(http://www.mmowned.com/forums/wow-gu...ink-build.html)
19 twink hunter/techniques/gear/spec - for newbies by Vemonous
(http://www.mmowned.com/forums/wow-gu...c-newbies.html)
Mage
Paladin
Priest
Rogue
Twink Gear Guide by Sicko
(http://www.mmowned.com/forums/wow-gu...ear-guide.html)
Lvl 19 rogue twink guide (gear). by Flawl
(http://www.mmowned.com/forums/wow-gu...uide-gear.html)
[Guide] 19 twink rogue - multiple gear sets - competitive WSG area by Syrzan
(http://www.mmowned.com/forums/wow-gu...-wsg-area.html)
[Twinks!] The PERFECT 19 Rogue Twink 2.4.3 Patch by Rapt0R
(http://www.mmowned.com/forums/wow-gu...4-3-patch.html)
Shaman
Warlock
Warrior
Multiple
Level 1 twink guide by Rohi
(http://www.mmowned.com/forums/wow-gu...ink-guide.html)
29 Twink Guide melee classes by Rapt0R
(http://www.mmowned.com/forums/wow-gu...e-classes.html)
[Guide] Priest/warrior/druid 19 twink guide by Outsider141
(http://www.mmowned.com/forums/wow-gu...ink-guide.html)
Twink Guide by Raidings Overrated
(http://www.mmowned.com/forums/wow-gu...ink-guide.html)
lvl 1 twink guide (selfmade) by mordo
(http://www.mmowned.com/forums/wow-gu...-selfmade.html)
[GUIDE] How To Make A Lvl 1 Twink! by 7itanium
(http://www.mmowned.com/forums/wow-gu...l-1-twink.html)
29 Twink Guide by Nightdart
(http://www.mmowned.com/forums/wow-gu...ink-guide.html)
lvl 1 twink guide by Flame_Warrior
(http://www.mmowned.com/forums/wow-gu...ink-guide.html)
My Level One Twink Guide by Zero-Cool
(http://www.mmowned.com/forums/wow-gu...ink-guide.html)
Miscellaneous
Lvl 19 Twink Guide (Flag Runner) by Flame_Warrior
(http://www.mmowned.com/forums/wow-gu...ag-runner.html)
Horde
Alliance
Nymphs' Alliance Rogue Twinking guide, 19. by Nymphx
(http://www.mmowned.com/forums/wow-gu...uide-19-a.html)
Credits go to me and shaman1234(Whether he likes it or not).