Rice University
Galileo Project: The Ptolemaic System
This site from The Galileo Project of Rice University provides this discourse on the Ptolemic System that attempted to explain the motion of heavenly bodies. Pictures, charts, and links are all provided for additional information.
University of St. Andrews (UK)
University of St. Andrews: Claudius Ptolemy
This site, which is provided for by the University of St. Andrews, contains biological information as well as the works of Ptolemy.