Nine Planets
The Nine Planets: Uranus
An excellent report on the planet Uranus. The site includes detailed information about the planet as well as links to information about Uranus moons, unmanned probes sent to explore Uranus, and an extensive set of images of the planet.
University of St. Andrews (UK)
University of St. Andrews: Orbits and Gravitation
A page describing the physics, mathematics, and historical figures associated with planetary motion, satellite motion, and universal gravitation.
Cornell University
Cornell University: Astronomy: Orbital Motion and Kepler's Laws
At this site from the Astronomy Department of Cornell University, Kepler's three laws of planetary motion are stated. There are brief explanations of each, along with links to additional information on related subjects.