How old are you? If you are in high school preparing for college, then choose a college that offers French. Classrooms are the best way to learn a language.
If you are past college or attending a college that does not offer French, then you still have options. First, if you are near a university, you can go to the university and tell them that you would like to meet with a French (or French-speaking) exchange student for a language exchange. This will allow you to learn French and practice it with someone who speaks it. You may also have to help them learn your language.
If you are not able to do that, then go here:
http://www.mylanguageexchange.com/Learn/French.asp
It is a website language exchange.
If you want a few sources to get you started first, try these:
http://www.bbc.co.uk/languages/french/
http://french.about.com/
http://www.jump-gate.com/languages/french/
Good luck!