If you don't have any time to look at any other links, then Windows to the Universe is the place for you. It is the ultimate web site about space. The site offers a choice of appropriate educational levels: beginner, intermediate, or advanced. It is brought to you by the National Earth Science Teachers Association.
Useful Daily Space Data
The sunrise, sunset, moonrise, moonset and twilight time tables for your location from the United States Naval Observatory can be a useful classroom tool. Also included are important dates, positions of the sun and moon, and eclipse information.
Discover the Electronic Picture Books and tutorials from STScI (Space Telescope Science Institute). The Electronic Picture Books contain full color images and informative text designed with powerful navigational tools. The library is continually growing with subjects such as geography, planetary science, and astrophysics. There are views of Earth and images taken by the Hubble Space Telescope.