A very easy site to navigate and useful for obtaining current science articles. The site can be used by both teachers and students. Lesson plans, software reviews, and experiments are available for teachers to use. The Journal online is a great database and launching point for other biological science sites. One unique feature is a link to a site with CAD designed molecules.
Sample worksheets are available.
Tests and lab experiments are organized by concept, and this site could be used a test bank. Similar to Discover online, this is ChemMatters online. Designed as a high school science magazine, ChemMatters has current chemistry news, educational activity resources for all grade levels, and links to other ACS sites. A great place to get some new ideas. They provide problem sets organized by concept, which give multiple choice questions, and then the correct answer with the reasoning.