Business problem... please help me

I am creating a new business that deals with websites and design in general. I just have one problem… I am not yet 18. Does anyone know if you can create contracts if you are under the age of 18? I usually am subcontracted and dont have to deal with any of the contracts or legal issues but i need to know if it would be a problem if I was under the age of 18 to make a contract.

If so, can you guys show me some of the contracts you get your clients to sign for me to use as a reference. I am new to all of this legal stuff so if any of you have ANY advise please let me konow. O and by the way I live in America if that changes anything.