Emory University
Emory University: Something About X Rays for Everybody
A summary of a century of research regarding X-rays. Discusses the discovery and applications of X-rays. Includes some ideas for exploring and investigating X-rays.
University of Colorado
University of Colorado: Physics 2000: X Rays
Here's a really simple demonstration of a fluoroscope. There are links to more information about the uses of X-rays as well.