One area that the gunsmithing schools touch on, but some don't go into enough (I have been told) is running a business. If possible, take some courses in doing that, if not before gunsmith school, then at least before you open a shop.
I opened a thread on another site, and I hope the moderators won't mind if I point to it. It has been very interesting and you might be interested.
http://www.thehighroad.org/showthread.php?t=637143
Jim