If this is your first experience try The Moorings or Sunsail. There vessels are in good shape and less for you to worry about. The BVI is a good place to start since you can see everything and where you will wind up at the end of the day. Many harbors have mooring balls to pick up, free during the day and $25 overnight.
We are Mooring owners in Road Town,Tortola. If you feel confident enough you can try Footloose or go to
www.sailonline.com and deal directly with the boat owners who have sailboats available in the BVI. Generally The Moorings boat owners sell their unused owners time for about 1/2 the going charter rate of The Moorings and Sunsail rates.