City University of New York
Classification: Bringing Order Out of Chaos
A self-directed module on all aspects of biological classifications that covers the species problem, diversity and chaos, cladistics, putting things in groups, and so on.
Wikimedia
Wikipedia: Binomial Nomenclature
Wikipedia, an open-source encyclopedia, offers great information on the classification system used in Biology. Covers the benefits of the system, history, and general information on the whole system together.