In Defense of Science Fiction:An essay on science fiction and literature by critic and science fiction historian John Clute.
Classics of Science Fiction: Identifying the classic books of science fiction.
Council for the Literature of the Fantastic: A very scholarly approach to fantastic literature.
Definitions of Science Fiction: More than fifty definitions of science fiction from authors.
Her World Exploded: Essay taking the view that science fiction is about how you read a story, not how it's written.
Kittywompus Tracks Fanzines: A weblog providing critical reviews of paper and electronic SF fanzines.
Novelhead: Original science fiction, humour and tips for writers.
Quantum Cosmos: Bibliography, essays and literary writings by Douglas A. Mackey, as well as reviews of books on physics and consciousness.
Science Fiction and Society: Discusses science fiction and its ties to human culture and social issues. Features new articles weekly, discussions, polls, and links.
Science Fiction Research Bibliography: An extensive bibliography of printed reference material related to science fiction deemed valueable for research into the subject, from books available at Washington State University's Holland Library.
Science Fiction Studies: Website contains all article-abstracts and full texts of all reviews published in the journal since its founding in 1973, as well as featured essays, documents in the history of sf, and a bibliography of sf-criticism.
scifi/Hack1: For users learning how to write or critique science fiction.
The Templeton Gate: Essays and reviews of Science Fiction authors, as well as SF films and television.
Tonya's Sphere of Influence: A brief historical survey of women writers of science fiction.