The author of our text, William K. Hartmann, has a really nice site where you can read about his research and also see small color versions of some of his astronomical paintings, some of which (in black and white) illustrate the text.
Dr. Hartmann is associated with the Planetary Science Institute in Tucson, Arizona.
Of course, one of the most basic sites is NASA.
Most of NASA's planetary missions have been managed by the Jet Propulsion Laboratory.
Students for the Exploration and Development of Space is an interesting organization. Perhaps you would like to start a chapter here at Bates....
The Galileo Project at Rice University is an excellent source of information about the life and time of Galileo and his contemporaries.
The Clementine mission to the moon was managed by the Naval Research Laboratory.
The Lunar and Planetary Institute in Houston is another good source of information.
The U.S. Geological Survey Flagstaff Field Center houses the Branch of Astrogeology, a valuable source of mapping information.
Sky Publishing Corp. is a good source of books, slides, software, and similar things. They also publish Sky & Telescope Magazine.
The Astronomical Society of the Pacific has a good catalogue of books, slides, teaching aids, and so on. They publish journals for their members.
The Planetary Society is also a membership organization and a sort of "lobby" group. They get involved in a lot of interesting efforts.
Finley-Holiday Films is a prime source of pictures from NASA space missions.
The Space Telescope Science Institute is the headquarters of the Hubble Space Telescope.
The Chandra X-Ray Telescope is the latest big telescope in space.
The Astronomy Picture of the Day is a great place to bookmark and check out to see what is happening in astronomy.
The Two-Micron All-Sky Survey is an ongoing project to survey the sky in the near infrared which is producing some great pictures.
You might check out Today's Space Weather to see how the Sun is behaving and interacting with the Earth's magnetic field.
Here is a nice Interactive Map of the Moon that Brian Rimm '05 found for study.
Here is a nice Program to calculate the sizes of impact craters predicted by various models.