The Center for Social Media at American University has published a Code of Best Practices in Fair Use for Online Video:
This is a guide to current acceptable practices, drawing on the actual activities of creators, as discussed among other places in the study Recut, Reframe, Recycle: Quoting Copyrighted Material in User-Generated Video and backed by the judgment of a national panel of experts. It also draws, by way of analogy, upon the professional judgment and experience of documentary filmmakers, whose own code of best practices has been recognized throughout the film and television businesses.
I wish we had a roadmap like this when we launched Ourmedia.org, the first video hosting site, back in March 2005…. All video producers and content creators should absorb this common-sense set of principles.