3 links
Cambrian Geography
vishnu.glg.nau.edu
Description and maps of the continents as they existed at the time.
The Cambrian Explosion
hoopermuseum.earthsci.carleton.ca
Virtual museum exhibit about the major faunal radiation that occurred in the Cambrian.
The Cambrian Period
ucmp.berkeley.edu
University of California Museum of Paleontology introduction to the Cambrian.