I would go to your local library and get general books about opening such a business in your area/state as there are lots of laws and stuff that have to be met first before one can start really planning. You'll need certain licenses and maybe even education. They might have plans already written out too.
http://www.rehabnetwork.org/success_...ld%20Yoder.htm
http://ohioline.osu.edu/cd-fact/1101.html