Tough question with a broad scope. Well you can start with a few business courses, know how to read plans, know how to schedule, you should know a little bit about all the other trades - mechanical, plumbing, electrical, framing, drywall, painting, etc..etc. Then you'll need to get a contractor license (maybe that's what you said in your post) - depending on where you are will depend on what you need to get. Contact your State Dept of Labor. Then get a local business license - sometimes not needed. Contact your building department for their inspection listing. Learn how to do take-offs and bids professionally. Know how to bid subcontractors fairly.
This could go on and on.. could you be more specific?