University of California
Univ. Of Cal Berkeley: The Comet's Tale
Site provides extensive information in the study of comets. Includes excellent graphics that depict what comets look like as they travel through the solar system. Also includes information on how comets may have effected the Earth's...
Other
University of Leicester: Comets
A detailed look at comets. Content outlines our observational history, as well as the origins of comets and an explanation of the appearance of comets.