Link: James Webb vs Hubble
[Interactive Flash presentation comparing how the specifications of the two telescopes and their operation]
Other NASA interactive resources: Link: NASA - NASA Interactive Features
I've always been a huge fan of the Hubble Space Telescope, I think it is a wonderful piece of engineering which has really helped us to see further and deeper into our universe.
Anyone interested in the Hubble telescope should check out the Mission Highlights for the STS-125 mission, on NASA Television's YouTube page. Do a search for 'STS 125 mission highlights', and enjoy. It is a fascinating insight into the challenges, complexities and delicacies in working with the telescope and upgrading it. They even replaced computer boards in outer space!
Link: NASA Television's YouTube Page.
I watched this mission right the way through on the NASA TV live stream, they have outstanding commentators who describe everything the astronauts do on a space shuttle mission.