You really should check out my sister in law's blog... http://fiber-fever.blogspot.com/She's trying to figure out how to make a spinning wheel. You might get some ideas. :)
I've thought about doing this, but I keep hearing that it's hard to make a good wheel that's easy to use and spins well. Actually, my biggest problem is a lack of tools of any sort. My husband isn't exactly what you'd call handy, despite being a construction major.