Ducksters
Ducksters: Biology for Kids: Non Flowering Plants
On this site, learn about the biology of non-flowering plants including gymnosperms, conifers, cones, seed, spores, ferns, and mosses.
University of California
Ucmp: Introduction to the Cenozoic
A good brief review of The Cenozoic Era, which also includes links to more detailed information as well as a chart of its subdivisions.