Cycadophyta: Fossil history.
Introduction to the Cycads: An excellent place to begin learning about the Cycads
PACSOA - Cycads: Includes many articles, detailed species accounts, and images. From the Palm and Cycad Societies of Australia (PACSOA).
The Cycad Pages: Extensive botanical database on the known cycads, including identification and classification, ecology and conservation, cycad evolution and the fossil record, geography and distribution, and horticultural information.
The Cycads: Fossils of the Past: An introduction.
University of Georgia Greenhouses - Non-flowering Plants: Includes images of the cycad collection.
Virtual Cycad Encyclopedia: Good source for information on Cycads. Includes taxonomy, biology, photos, links.