Hyperlinked Human Histology: Easy to understand cartoons explaining cells and organs of the immune system. (From A.M. Campbell of Davidson College.)
Molecular Movies: Scroll to the bottom of this page to find entertaining and informative animations that demonstrate visually the recombination of antibody genes, B and T cell selection and activation, antigen presentation, etc. (Also from A.M. Campbell of Davidson College.)
Histocompatability Molecules and Antigen Presentation: An good introduction to MHC molecules and Ag presentation with internal links to sites defining and describing all important terminology and concepts mentioned in the main text. (From John W. Kimball's Biology Pages.)
The Complement System: Another good overview from Kimball.
Immunology Bookcase: Summarizes many of the topics covered in class. (From Drs. Tim Lee and Angela McGibbon of Dalhousie University.)
White Cell Basics: Nice color images of white blood cells (neutrophil, eosinophil, basophil, monocyte, lymphocyte). (From the University of Virginia.)