I took four years of French in high school. You can buy tapes, CD's and videos. Even download lessons on your computer. But the best way to learn is to either move to France or take a class. There you can practice on each other. Your teacher can listen to you and correct you when and if needed. But even then, you'll only learn what is called the 'upper class' french. If you saw afrenchie and Alizéeclochette in conversation you may not be able to keep up because of the slang words they might use.
As a Spanish teacher once told me, 'The kids who take Spanish learn spanish, they do not learn mexican.'
I commend those who want to learn French. It keeps your mind active and it broadens your mind. It also helps to bridge the gap between us and Europe. Plus it is so cool to be able to listen to Aliz'ee and know what the heck she's saying.
