Free Online Astronomy Course

This Web-based course, or "webbook", is a college-level, semester-long, non-calculational introduction to astronomy (it may also be suitable for a high school course). It was initiated while Scott R. Anderson, Ph.D. of Sandia Research and Computing Associates in Albuquerque was a teaching affiliate in the Physics Department at Emory University in Atlanta, Georgia.

http://www.opencourse.info/astronomy/introduction/00.preface/