This is a list of noted science-fiction authors (in alphabetical order):
A useful book for looking up authors is A Reader's Guide to Science Fiction, by Baird Searles, Martin Last, Beth Meacham, and Michael Franklin (1979). It also tells you whom else you might like if you like one author.
Other invaluable works include The Encyclopedia of Science Fiction, edited by John Clute and Peter Nicholls (2nd. Ed. 1991), The Mammoth Encyclopedia of Science Fiction, edited by George Mann (1999) (ISBN 0-7867-0887-5 or ISBN 1-84119-177-9), and Twentieth-Century Science-Fiction Writers, edited by Curtis C. Smith (1981) (ISBN 0-312-82420-3).