AFI Film Catalog. "The most authoritative filmographic database on the web." Includes detailed synopses and other information about every American film production.
Alt Film Guide. About alternative films.
American Silent Feature Film Survival Database: The Survival of American Silent Feature Films: 1912-1929. Comprehensive survey of surviving American silent films. Library of Congress site.
Anyclip. Find clips from movies: "we make movies searchable and discoverable from beginning to end."
Audiovisual Citation Project. British Universities Film & Video Council guidelines for the citation of moving image and sound.
A/V Geeks. All about out-of-the mainstream films,with DVDs for sale.
British Pathé Film Archive on YouTube. All 85,000 newsreel films spanning the years from 1896 to 1976.
CineFiles. University of California Berkeley Art Museum & Pacific Film Archive. Includes scanned reviews and other film related writing, and citations to copyrighted material.
Cinema Treasures: "Your Guide to Movie Theaters."
Critical Commons: "a public media archive and fair use advocacy network that supports the transformative reuse of media in scholarly and creative concepts ... goal is to build open, informed communities around media-based research , teaching, learning, and creativity."
Dream Factory on the Nile: Posters and Memorabilia from the Golden Age of Egyptian Film (Stanford University).
eMoviePoster.com: Commercial auction site with extensive archive of past results in high resolution (although watermarked).
EUscreen. "Free online archive of videos, stills, text and audio from European broadcasters and audiovisual archives."
Facets Multimedia. Buy and rent DVDs.
Heritage Auctions: keeps an archive of previous auction results with high-res scans, including film material and posters.
Internet Archive Moving Images. Non-profit site with free access. Much public domain material.
Internet Movie Database. The premier site movie information.
Lantern. Collections of the Media History Digital Library, an open access database of media periodicals in the public domain. Includes film magazines.
Learn About Movie Posters (LAMP): Resource for discovering information about "film accessories," in particular, movie posters.
Library of Congress Motion Pictures & Television Reading Room. Resource page.
Library of Congress Films and Videos online: Includes historic films going back to the beginnings.
Media History Digital Library. Digitized public domain periodicals and other material relating to film.
Moving Image Research Collections. Digital Video Repository from the University of South Carolina.
OpenFlix. Directory of movies commonly thought to be in the public domain. Includes copyright information for US and abroad.
Reel Classics Copyright information for film clips and movie screenings.
Sulphur Springs Collection of Pre-Nickelodeon Films. Digitized turn of the 20th century short films.
Swank Motion Pictures: Movie distributor and public performance licensing agent.
"A Trip to the Moon" (and Five Other Free Films) by Georges Méliès. Available at Open Culture.
Who's Who in Victorian Cinema. "A biographical guide to the earliest years of moving pictures, 1871-1901."