How do I start?
I think you''re on the right track. Make as many sailing contacts as you can, especially nearest to where you live. Captains can almost always use another hand on board and the best way to learn is by doing.
However, if you really want to get off to a good start, you might want to consider taking formal lessons.
There are a couple of major schools, I''m thinking of J World (www.jworldschool.com) or one of the American Sailing Association schools (www.american-sailing.com). Usually, they have a 1 week basic boating course that could give you a pretty good level of knowledge for helping out on other people''s boats. Then, they usually have a more advanced course that would qualify you for doing a "bareboat" charter (charter with you being the captain). After this level of instruction, you''d be pretty qualified to own and sail your own boat.
Another alternative is to charter a boat through someone like the Moorings, in the British Virgin Islands (www.moorings.com), and rent a captain along with it (an additional 100-200 per day). If you tell the captain that you''re hoping to learn enough to bareboat then they''ll show you the ropes so to speak. The Moorings also will match you up with other people who want to learn, if you''re by yourself and getting your own boat for the week is too expensive.
Other than that, keep doing what you''re doing, crew on other people''s boats as much as you can, read some basic books like Chapman''s Piloting and that will get you started.