Film

Internet Movie Database http://www.imdb.com One of the largest movie websites in the world.
Backstage West http://www.backstage.com A popular acting resource website.  Has listings for film and television casting call notices as well as professional information on the performance craft.
Film.com http://www.film.com Popular film website.
American Film Institute http://www.afi.com Website to the prestigious American Film Institute.  .

British Film Institute http://www.bfi.org.uk/ The British doppelganger to AFI .
Box Office http://boxoffice.com Site for Box Office magazine.
Movie City News http://www.moviecitynews.com "Hollywood's Homepage" site dedicated to business and casual news about Hollywood.

The Hollywood Reporter http://www.hollywoodreporter.com/hr/index.jsp Website of one of the industry's premiere business news paper.

Variety http://www.variety.com/ Website of another popular industry's business news paper.

Television

TV Guide http://www.tvguide.com The webpage of one of American's most popular television show listing magazine.
Television Without Pity http://www.televisionwithoutpity.com/index.php An offbeat independent style website covering television show news.
Museum of Broadcast Communications http://www.museum.tv/ History of television.
TV.Com http://www.tv.com Gossip news and buzz about television shows.
Academy of Television Arts & Sciences http://www.emmys.com/ A great resource of television archives and the foundation's efforts to preserve television history.  Home of the famous Emmy award.

Independent Television Service http://www.itvs.org/index.htm Webpage for ITVS, who funds, presents and promotes independently produced programs for public television.