Epicurious dictionary -- much food info
Los Alamos physics archive -- bleeding edge scientific information -- much of which I don't understand. (Space-time foam?)
World Species List
SOAR: Searchable Online Archive of Recipes
Games Kids Play
The Times of India -- politics stranger by US standards than in most sf
AstroWeb: Astronomical Internet Resources
Useful equations for Science Fiction
Planet Creation Kit
World Building
World Builders
tree of life
The Flying Pig Campfire Song Book
newspaper, magazine, tv and radio web pages around the world. (I think the paper in Antarctica has gone inactive, unfortunately.)
Bartlett's Quotations
The Lucky Mojo Curio Co. Information on magic, folk religion, herbs, etc. Also stuff for sale.
Science Fiction Resource Guide
Science-fiction and Fantasy Writers of America (SFWA)
Black Holes - Response Time Tracker. Tracks how long it takes for sf magazines to respond to submissions.
The Mudcat Cafe/Digital Tradition - folk music texts (and some audio)
The Critters Writers Workshop -- online sf/fantasy workshop with a very good reputation.
American Name Society
Canadian Society for the Study of Names
Placename Survey of the United States
Scottish Placename Society
Medieval Scotland
The Getty Thesaurus of Geographic Names.
The Calendar Zone
Newspaper Archives on the Web.
Brewer's Dictionary of Phrase and Fable
Encyclopedia Astronautica
Medieval Studies - Labyrinth
Medieval Feminist Index (MFI)
Astrobrowse
Ancient World Web
Internet Public Library (text)