PBS
Pbs Learning Media: The Beginnings of the Telescope
This animated essay from the NOVA Web site examines the design of Galileo's refracting telescope and Sir Isaac Newton's reflecting telescope.
Other
Meade Instruments Corporation: How Telescopes Work
This page explains in fairly simple terms the basics of telescopes. It includes information on the various types of telescopes and the factors people use to select the correct telescope for them. Meade is a leading telescope manufacturer.
University of Maryland
Optics Highlights: The Telescope
Part of an anecdotal history of optics and the study of light. Extremely thorough treatment of the invention of the telescope. Includes a short biographical sketch and discusses the work of Isaac Newton which focuses on his contribution...