University of California
Ucla: What Makes a Planet
This detailed essay defines planets and compares the characteristics to those of Pluto. Orbital graphs and background information clarify the change in Pluto's categorization. A copy of IAU's Resolution 5 is also contained in this essay.
Other
Iau: Pluto and Our Developing Solar System
Discover how varying view in regards to Pluto has changed views on our solar system.
TED Talks
Ted: Ted Ed: The Journey to Pluto, the Farthest World Ever Explored
Alan Stern explains how NASA's New Horizons mission will to allow us to see Pluto for the first time.