Here are a list of websites that i have used that have helped me in stages of all my coursework such as finding information on production companies, comparing other film openings to ours to add similar features and also finding out what age groups tend to watch certain genres.
Youtube
http://www.film4.com/
http://www.imdb.com/search/title?genres=documentary
http://www.slideshare.net/KamikazeWarBat/3-documentary-cc-target-audience-and-market-research