Definatly check zoning. I folded my detail shop a few years ago and called the city to ask if I could do it in my garage and they said no. The issue with it was they didnt want cars filling my drive way. I would get a license and insurace. If you get caught with out the icense the fine is more than the cost to get it. And insurance just in case someone gets hurt on your property your covered. When your at your lawers office for the license ask about getting incorperated. That way if someone tries to sue your company they cant come after your personal assets, just the businesses. Get a folder started at a cpa also. Gotta pay the tax man for all the money your gonna make. If you can get away with doing it "on the side" thats great. Good to have cash the government wont know about.