Here are a several great websites to learn more about butterflies.
Butterflies of North America
A USGS site consisting of constantly updated distribution maps, photos, species accounts, and species checklists for each county in the U. S. and state in northern Mexico.
Connecticut Butterfly Atlas
The Connecticut Butterfly Atlas was a five-year undertaking begun in 1995 with a primary goal of mapping the distribution of Connecticut butterfly species. The website includes methodology, summary statistics and distribution maps.
Massachusetts Butterfly Club
The Massachusetts Butterfly Club sponsors state-wide butterfly activities to promote education, conservation, interpretation, and fun!
North American Butterfly Association
The North American Butterfly Association (NABA) is a national, membership-based not-for-profit organization working to increase public enjoyment and conservation of butterflies. It has members throughout the United States, Canada and Mexico.
Vermont Butterfly Survey
The Vermont Butterfly Survey (VBS), a project of the Vermont Institute of Natural Science, is a five-year census to document the relative abundance and distribution of butterflies across Vermont.