University of California
University of California Irvine: Evolution of Mammals
A strong, comprehensive look at the evolution of mammals. Includes factors such as changing geologic structure of the earth and the different types found on different continents.
University of California
Ucmp: Eutheria: Systematics, Part
A cladogram that gives the evolutionary relationship between the different groups of mammals. Modern relationship drawing, somewhat difficult to interpret.
Other
Warrensburg Schools: The Evolution of Mammals
This site from Warrensburg Schools is a high school site that touches on most of the major information in the most common account of the evolution of mammals.
Other
Twow:the Gradual Evolution of Mammals
An interesting page, full of references that discusses the evolution of mammals. High level discussion.
Enchanted Learning
Enchanted Learning: The Evolution of Mammals
A good and easy to read history of mammals. Relatively brief discussion of the evolutionary history.