Druids are powerful in Warsong Gulch and Arathi Basin. In WSG they are quite possibly the best flag capturers, especially in the 10-19 bracket with travel form, making them the fastest players on the field.
Making a good twink is going to be expensive; and that's a fact. If you get the proper equips and enchants, it's gonna cost up to several thousand Gold. Saying that, it will be a great way to have fun when completed. G'luck
Popular Alliance choices are Night Elf, for the extra agility, and Human, for Every Man for Himself. Gnomes are also rather popular and dwarves make appearances here and there. Popular Horde choices include Blood Elf and Undead.
Every race has it's advantages and disadvantages, and your choice should be based largely on your play style.
Alliance
Human - The ability to detect stealth more adeptly than the other races is a bonus to survivability against other rogues. Every Man for Himself effectively allows you to have three trinkets, as it acts as an Insignia of the Alliance and shares the cooldown, too.
Dwarf - A survivability race, with more stamina and Stoneform, which will remove bleeds, poisons, and diseases and increase your armor slightly.
Night Elf - A very popular choice, Night Elves have the ability to Shadowmeld, which allows you to Prowl in combat. In addition, they have the most agility of any Alliance Race.
Gnome - The bonus to engineering for a gnome allows you to create higher-level Engineering items than the other races, however, you don't need to take up engineering in the first place. Escape Artist is a very nice racial ability that will remove all roots and snares (But NOT stuns!).
Horde
Orc - A high-stamina race with some nice racials. Blood Fury is nice for increasing your attack power and can give you the extra boost you need to take down other players. Hardiness will also reduce the duration of stun effects.
Forsaken - A very popular Horde race. Shadow Resistance will decrease the chance shadow spells hit you. Will of the Forsaken will remove charm, fear, and sleep effects on you, making for a potent combination versus Warlocks alongside Shadow Resistance. Cannibalize is a nice way to restore health without sitting down to eat, using a potion, putting stress on a healer, or running to a Rejuvenation powerup.
Troll - Many racials that benefit rogues. Berserking is a useful ability that will increase attack speed by amounts that vary depending on how badly injured the troll is. The highest possible bonus from Berserking is 30%. However, Berserking will cost you some Energy. Da Voodoo Shuffle is a new racial ability that decreases the duration of snares by 15%. Regeneration will increase your health regeneration rate by 10% and allow 10% of your health regeneration to take place during combat. While that may not seem useful at first it can save you in a pinch. Bow and Throwing Specialization will increase your ranged critical chance, be it with a bow or a throwing weapon.
Blood Elf - Arcane Torrent is the highlight here. Using it will silence every foe within an 8-yard radius and will also restore 15 energy. Magic Resistance will also decrease the chance that any spell will hit you by 2%.