Creating a digital coursebook for Bachillerato

Hi, I'm seriously thinking of creating my own digital coursebook for English bachillerato, according to Spanish curriculum. Obviously, all should be done with a Creative Commons license. The idea is to create materials (most likely with Malted) so that students don't have to buy a coursebook. Students would be given a CD (or USB pen) with the book contents and there would also be interactive exercises in our school's website. So far the big problem I've found is how to find audio and video that can be shared freely. I'm thinking of using TED talks, but I'd be grateful if someone could give some hints. Needless to say, materials would be shared with any school interested in this project.