University of Arizona
University of Arizona: Blood Types Tutorial
This site from the University of Arizona describes how blood type is passed on from parent to child. The tutorial covers the genetics of the ABO blood groups as well as Rh factor. There are even practice problems and blood type calculators!
Palomar Community College District
Palomar College: Table of Blood Type Frequencies
This site includes a listing of United States frequencies of the various human blood groups.
WebMD
Web Md: Blood Typing
Visit this site for a great article over blood typing tests. Read about the two types of blood typing tests (ABO and Rh tests), why the tests are done, how they are done, and risk factors. Also, view a chart that shows the compatibility...