If you are really serious (meaning you can stick with it), I suggest French In Action (FIA), which can be found on YouTube and other places, including here at learner.org. It consists of a total of 52 half-hour episodes, for 26 hours of language immersion. It is well worth going through them all.
If you know absolutely no French, you should look into Rosetta Stone to get acquainted with the language. Unfortunately, it is not free. Even with Rosetta Stone, I recommend FIA.