french.about.com is packed full of information for beginner to intermediate French learners as well as teachers of those levels. In fact, there is so much content there that listing it here would take too much time! Instead, this article will highlight some of the things you can find on the site, and leave the rest for you to find on the site.
Of special note are the start learning section, practice materials, teacher resources, audio lab, grammar section, vocabulary section, proficiency tests, verb conjugator and the quizzes and tests area.
There is a lot more there, and it's all accessible for free. :)
Learning French is an ongoing and involved process. You can't learn French overnight, and you probably can't learn on your own, no matter how many books and tapes you buy.
What you can do is use this free website to supplement your learning: to get another explanation of something you didn't understand, to get extra practice between classes, and to brush up on what you once learned but have now all but forgotten.
Learn French at About offers hundreds of lessons and thousands of sound files to help you learn French.