IMDB includes: "Top Hits" at the box office, reviews of movies and videos, news, and trailers. It is especially strong in providing cast and technical credits, and it also includes some information on television movies and mini-series.
Kodak was one of the great innovators of motion picture and video photography, and they are behind the creation this glossary of movie and video technology terms.
"DocuSeek is a search site for independent, documentary, educational and social issue video and films." Results provide the title, brief description, date, length, grade level, and a link to the distributor for that film.
"This site contains Episode Lists for over 2500 TV shows. Each list contains titles and airdates. For most of these shows there is also a more detailed episode guide at TV Tome containing guest stars and plot summaries." Works well for the latest shows and for many of the classic shows, as well. This isn't the place to come for detailed analysis, but rather for episode-by-episode information on a particular program.
"Promoting the study of media history from petroglyphs to pixels" is the stated aim of this website, based at the University of Minnesota. There is content spanning from the earliest media to the digital age. Ever wonder about the "origins of videotape recording"? That's the kind of thing you can learn about at this website.