Not that I'm needing it, but this is very helpful to those who do not know. Some people think that questing is the fastest, but I believe it slows you down.
I don't have a specific spot I go to for either Alliance or Horde to kill things, but I just run around and kill everything in my path. If you know where all the rare spawns are that helps a ton, I've learned them all over the years of leveling characters. Usually hit level 10 in about 15-20 minutes, really just depends if the class can dot or not and of course hunters are easy mode. From there like you said for Alliance I go to Deadmines and Horde I go to RFC. Usually in about two runs of soloing you are level 20 or 19, whichever you choose to do. For 29 I just do random dungeons once 20.
Once again though, very helpful. Glad you made this because I'm sure it will come in handy for a lot of folks.