Natural History Museum
Natural History Museum: Fossil Formation
As part of a larger online exhibit on fossils and what fossils are, this site specifically deals with the formation of fossils. A six-step, detailed chart is provided with specific information explaining each step.
Utah Education Network
Uen: Fossils Moldy Oldies
A good introduction to different types of fossils and how they form. There are also directions for making three different models of fossils.