Frank Potter's Science Gems is a good resource for physical science, life science and earth science resources. It also has a search function that searches over 14,000 science sources.
This is a great site for a teachers interested in geology. It brings up a multitude of images that show different rock formations and that illustrate different geological concepts.
This site is a great source for K-12 lessons in biology.
An online community of teachers and students using technology to promote and engage in science learning. The web site includes threaded discussion areas, organizing protocols, data submission, retrieval from interactive databases, background information on the research areas, and a publication area for students to submit their own research work.
Teacher-designed web quests for K-12 science
The home page for the National Aeronautics and Space Administration
The home of NASA's K-12 Internet Initiative
The Science Guy's home page. A great site for finding great ways to engage kids in science exploration.
Marine biology lesson plans from many sources
The U.S. Dept. of Education sponsors this home page listing many activities relating to science that you can do at home or in the community.
The home page for TV's Discovery Channel
The Franklin Institute Science Museum's Home Page brings exhibits, resources and fun to your desktop.
San Francisco's Exploratorium has exhibits, news and resources for young and old to explore.
NCSA's Multimedia Online expo, "Science for the Millennium" contains many pavilions of science and industry.
This is an online exhibition from the Smithsonian Institution's National Museum of Natural History.
The purpose of this site is to sensitize teachers and students to examples of the bad science often taught in schools/universities, in textbooks, and in the media.
This site from the Jet Propulsion Lab uses NASA photographs to simulate the solar system. Fire up the simulator and choose your planet or satellite and a place to stand.
The National Science Foundation's home page