Biology Pages
Kimball's Biology Pages: Mutations of Dna
This is a very informative site on DNA mutations. There is estensive information and helpful diagrams.
Other
Acadia University: Class Notes on Mutation
These class notes from a Microbiology course at Acadia University outline point mutations, frameshift mutations, mutagens, mutation rate, and mutant isolation. A good way to review already learned concepts.
Kansas State
Mutations, Mutagens and Dna Repair: Types of Mutations
Good explanation of the different types of mutations. Solid background on base-pair substitution.