Discovery Education - Science Homework Help - a resource provided by Discovery Education to provide science homework help to students of all grades
Engineering: Go For It! - a Web magazine, with online video throughout, produced by the American Society for Engineering Education (ASEE).
Fermilabyrinth - online games and activities that take you 'behind the scenes' at Fermilab
Howard Hughes Medical Institute - one stop site for biology homework. Browse submitted questions or get ideas for science fair projects.
learningscience.org - links to science interactives and resources
Math & Science 2.0 - links to math and science sites from this IETC 2008 session
National Geographic Kids - includes extensive coverage of science, geography, history, and more, with articles, maps, photos, and videos
PBS Kids Design Squad Nation - an engineering-based reality show for kids. Each episode pits two teams against each other to design solutions to problems ranging from creating usable furniture from cardboard to tricycle-based drag racers.