US Department of Energy
Fus Ed Web: Physics of a Fundamental Energy Source
An excellent resource on nuclear fusion! Using incredible graphics and excellent discussion, this site (with its several pages) provides an exhaustive online course on the topic. Click on the link for "a Guided Tour" and begin.
Other
Princeton Plasma Physics Laboratory: Fusion Basics
A wealth of background information on nuclear fusion and its potential use as a commercial energy resource. The advantages of nuclear fusion over other resources, the conditions required for its successful implementation and the future...