I highly recommend LiveMocha.com for learning languages. It has free lessons, paid courses and you can even pay for private lessons. You do quizzes to see how well you've remembered the words and phrases. Best of all you record yourself reading a prescribed text and native speakers review your recordings and give you feedback! Having native speakers critique your speech really helps with pronunciation, something impossible to do with books and apps.
There are three free levels of French there and many other languages for other budding polyglots.