The great thing about the music business is that it's a constant learning process. The film thing is a little newer on me too.

I honestly have not seen many jobs in the film area but maybe this will help??

http://www.berklee.edu/careers/film_scoring.html

I think that if you are in school, studying music business would be the best place to start and so you will have the background. Otherwise, if you studied something else, maybe your advisor or alumni affairs director could help you will setting up an internship program at a Publishing Company. Publishing Companies handle the licensing aspect of film use (I hope I am getting closer to what you are looking to do - I thought you meant you wanted to become a Music Supervisor on a show or movie?? I apologize if I was off the mark on that.)

To become a Music Supervisor, they may want to see some music background as well as some of the business and legal side. Interning is a good way to get the real life experience. Publishing will expose you to the legal side.

Please let me know if I am hitting this nail yet - I really do want to help you! Darcie