OK, so during last summer I did some work for a friend and made some money. This was good because a. I got some money and b. I got some real world experience and practice at things that can get me more money in the future. This coming summer I am going to do the same, except that I want to open up my clientele base to everyone. I will be doing guitar setups/mods as well as some tracking/reamping mixing if by that time I have my new amp. Do I need a Business License? Will I need Insurance? What else will I need?