NASA
Nasa Space Science Data Archive: Pluto
This site, which is provided by the National Space Science Data Center of NASA, is a site with detailed information about Pluto, including planned missions to explore the planet in greater detail.
Johns Hopkins University
New Horizons Website
This site from the Solar System Exploration section of NASA provides an overview of the space mission to Pluto, Charon, and the fringes of our Solar System. It describes the Kuiper Belt, and the objects involved with it, provided links...
Arizona State University
Mars Global Surveyor: Kuiper Belt Objects
This site describes the extended belt of small bodies residing just outside the orbit of Pluto, the Kuiper Belt.