General Science:

Mad Sci Network 
general science education site with answers to common science questions, science news, and science fair project ideas as well as a place for posting science questions

The Naked Scientists 
weekly podcast of science news discussed in simple terms as well as a weekly "do-it-at-home" project demonstrating a scientific principle

PBS
links to science-related program sites which often include synopses of current topics and bibliographies

"Science Fair Projects" - University of Medicine and Dentistry of New Jersey science fair resource page hosted by UMDNJ; has links to many sites providing science fair project ideas and other resources

Science News For Kids  news, articles, science fair ideas, activities, etc.

Science.gov:  FirstGov for Science
links to science information from various US Government agencies, grouped by scientific topics

Scientific American
popular monthly science magazine; web page includes brief articles on current science news, previews of articles available in the magazine, an editors' blog on current science topics, and a weekly podcast discussion of current topics in science

"Talk of the Nation, Science Friday" weekly radio program discusses newsworthy issues in science; web page includes a downloadable archive and links to related resources;  the Science Friday Kids page is based upon the same programming with a program archive grouped by topic and additional resources