I use Recruit-A-Friend to do 1-60 in 8-12 hours with the help of a level 60+ warrior, mage, paladin, or warlock (or another class capable of aoe farming). Rogues work due to Fan of Knives but it goes slower than classes like Warrior, Mage, Paladin, and Warlock.
For horde, this is what I do:
10-17- RFC Ragefire Chasm
17-25- SFK Shadow Fang Keep
25-30- RFK Razorfen Kraul
30-33- SMGY Scarlet Monastery Grave Yard
33-40- SMC/SML/SMA Scarlet Monastery Cathedral / Scarlet Monastery Library / Scarlet Monastery Armory
40-48- ZF Zul Farrak
48-52- Maraudon
52-56- BRD Blackrock Depths
56-60- Stratholme
I've found that to be the most effective.
As a warrior I gather a lot of mobs, I have a shield spike on my shield, I get them right in front of me and use Shock Wave, if you're not prot then thunder clap will work but not nearly as well. I suggest respeccing prot.
As a paladin I gather a lot of mobs while using Sacred Shield on myself, I keep the devaura up, I use consecretion to down the mobs. It works by the far the best as prot spec.
As a mage I throw up Frost Armor and keep Ice Barrier up at all times, I frost nova all of the mobs after gathering a bunch and then use blizzard to burn them down.
As a rogue I use sprint to gather mobs, evasion once I have a lot on me, and start spamming Fan of Knives.
I have yet to do this with any other classes but will post guides for each class eventually.
Here is a video I filmed of 10-17 in RFC using a warrior. I will eventually make a video for each instance leading up to 60.
[ame=http://www.youtube.com/watch?v=pk6F94Whoa0]YouTube - RAF Power Leveling 10-17 Horde : AOE Farming Ragefire Chasm : 1 Level Per 6 Minutes[/ame]