This is an advertisement for a series of resources on using planetarium materials in the classroom. Good beginner-level site. The best site on the entire WWW for explaining the motion of the sun in the sky. Contains both conceptual and technical explanations. Macintosh software is not listed here.
Redshift is a planetarium program which can put the user on any object in the solar system.
Could be useful for simulated experiments. Hands-On Universe, a program of the Lawrence Hall of Science and NSF, attempting to build a nationwide collaboration of high school astronomy teachers. The Universe in the Classroom, a free newsletter for educators, is available from the Astronomical Society of the Pacific. An exciting remote-control observatory site. Sign up to control and take photographs over the web.