Best Answer: The first thing you need to do is to learn all there is about the trade. Then you go to contractor school(short course) to learn the legal aspect of handling contracts before taking the contractors exam pertaining to roofing and/or general contractor field. You are tested on all aspects of your trade including building codes. If you pass the exam and pay your fees and post your bond, you become a licensed contractor. Then you need a lot of money to buy equipment,rent a place to work out of, hire employees, pay liability and workers comp insurance and advertise.. Hopefully you can find enough work to pay the bills and keep the business open and have some money left over for you. The contractor generally just oversees the job while it is being done as he has many other things to do such as look for new jobs,write estimates,order materials etc.