Australian Museum
Australian Museum Society: Arthropods
A description of what arthropods actually are and a discussion of their origin, as well as some info on research.
Other
Natural Perspective: Joint Legs (Arthropoda)
A brief description of arthropoda and their population on the earth today. Som pictures of examples of the different classes of arthropods. (Includes insects, arachnids, crustacians, and malacostraca.)