Butterflies and Moths of North America:Comprehensive guide to the Lepidoptera of the United States and northern Mexico, including a photographic identification guide, county checklists, and distribution maps.
Butterfly Sightings Listing Software: Software to organize sightings and photos. Includes databases for North American butterflies, dragonflies, birds, and mammals.
Jim P. Brock - The Butterfly Man: Personal page of the co-author of several popular butterfly books.
Kenn Kaufman - Butterflies: Brief information on how to look for and identify butterflies.
Kim & Mike on the Road: Photo gallery of butterflies of northeastern Mexico and the Lower Rio Grande Valley.
North American Butterfly Association: A membership-based not-for-profit organization working to increase public enjoyment and conservation of butterflies.
Priscilla and Hank Brodkin's Site: Butterfly images, mostly from Arizona and Mexico, and information about the Butterflies of Arizona field guide.
The Butterfly Digest: Recent messages from many different regional butterfly and odonate e-mail groups.