AllMusicals.com: Grease: Site includes lyrics for all songs.
Grease: Official site of the British touring production includes ticket information, schedule, cast and crew, and games.
Grease @ Blenheim High School: Site for the 2004 Blenheim High School production includes synopsis, cast and crew lists, and downloadable photographs.
Moonstruck Drama Bookstore: Grease: Brief history of the musical by Jim Jacobs and Warren Casey, plus links to cast albums and sheet music.
StageAgent.com: Grease: Plot synopsis and character descriptions for Grease, including voice part, dancing difficulty and summaries for each character.