Alphabetical listing from the University of California of info on each of the animal phyla. Includes scientific and common names and photos. Characteristics of each group are explained in detail.

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.

The Tree of Life Web Project contains information on living organisms including their history and characteristics. Over 3,000 web pages are linked together uniting all living things.