The following web sites provide more information about learning objects.
 
Academic Advanced Distributed Learning Co-Lab
University of Wisconsin-Milwaukee Center for International Education
Wisconsin Online Resource Center

Check these other web sites for useful resources:
 
BiosciEdNet (BEN) Portal
FDA "Bad Bug Book"
Food Safety Inspection Service Image Library
Health Education Assets Library (Heal)
International Veterinary Information Service
Multimedia Educational Resource for Learning and Online Teaching (Merlot)
Microbe Library
USDA Agricultural Research Service Image Gallery