Information about making quilts to sell? Please help!?

I am interested in making quilts to sell, and was wondering if you use a pattern from a book or from the internet do you have to get permission from the creator of the pattern before you sell the quilt? Also, if you use specialty fabrics (I am wanting to make a quilt with an NFL team fabric), can you sell them? If you need permission, how do you go about obtaining it? Please advise!