Bee Biology and ID
Apoidea of Maryland, images and descriptions from Sam Droege
Bee Basics: an Introduction to Our Native Bees, Pollinator Partnership and USDA Forest Service
Bee Genera Cards, The Great Sunflower Project
Bees of Maryland: A Field Guide, North American Native Bee Collaborative
Bees of Ohio: A Field Guide, North American Native Bee Collaborative with Schnebelin and Spring
Bees of the Great Lakes Region and the Wildflowers that Support Them, Michigan State University
Bugguide.net: upload bee images for identification help
Bumble Bee ID Manual, MN Bee Lab
Conserving Wild Bees in Pennsylvania: Penn State University
Conservation and Management of North American Bumble Bees: USDA Forest Service and NatureServe
Discover Life on-line key to bee genera
Discover Life on-line keys to bee species
Guide to Specialist Bees of Ohio
Oligolectic bees, Illinois wildflower guide
Supporting Native Bees: Our Essential Pollinators, University of Wisconsin-Extension
Specialist bees of the Mid-Atlantic and Northeastern United States (including host plants), Droege and Fowler
Understanding Native Bees: University of Maine
The Very Handy Bee Manual, Sam Droege et. al.
Wild Bees of New York, Sharp-Eatman Nature Photography
Wild Pollinators of Eastern Apple Orchards and How to Conserve Them: Cornell University