From Dmoz.org directory:

• Agatha Christie - Official site includes biography, bibliography, stories, and information about the Agatha Christie Society.
• Agatha Christie - Features author information, books, links, and chat.
• Agatha Christie - Features a collection of essays, a booklist, and television and film information.
• Agatha Christie - Bartleby.com - Brief biography and list of her works.
• Agatha Christie - Icelandic Homepage - In English and Icelandic. Information on the author, her books and the detectives, quotations, and trivia.
• Agatha Christie - Queen of Crime - Fan page including a biography and links.
• An Agatha Christie Booklist - Contains information about the style of each mystery, main character, and any recurring characters.
• Agatha Christie Index - Biography and annotated list of novels, short stories and plays.
• Agatha Christie Mallowan - Features a biography, bibliography, photos, and an interview.
• Agatha Christie Online - Biography, bibliography, and information about the novels and short stories.
• Agatha Christie: The Torre Connection - Author's biography with a focus on her connection with the All Saints Torre Torbay church in Torquay, UK.
• Allreaders Agatha Christie Spotlight - A detailed analysis of the plot, setting, characters, theme, and structure of her greatest novels, and links to similar works by other novelists.
• And Then There Was Agatha Christie - A site containing interesting and not very well-known facts about Agatha Christie and her works.
• Czech Page for Agatha Christie - In Czech and English. Biography, information on film and TV productions of her work, the characters, and an opportunity to rate the books.
• Delicious Death - Complete bibliography, organized by date and character, with synopses and cover art.
• Free Online Library: Christie, Agatha - Biography, photograph, and an e-text (The Mysterious Affair at Styles).
• Herbert P. Holeman's Searchable Database - Database of novels organized by title, protagonist, year published, and type of crime.
• Literature Network: Agatha Christie - Extensive biography and a searchable collection of works.
• Mysteries by Agatha Christie - A small personal site with some online texts to read.
• Web Companion to Agatha Christie - Contains a chronology of mystery novels, plays, and short story collections.
• The World of Agatha Christie - In French, German, Spanish, and English.