Here are some links that may interest you. If you're looking for a nursery, check out our page of Nurseries. If you're looking for a place to find butterflies, check out our page of Hot Spots.
North American Butterfly Association - NABA
The Lepidopterists' Society - LepSoc
Dallas County Lepidopterists' Society - DCLS
Butterfly Enthusiasts of Southeast Texas - NABA-BEST
South Texas Butterfly Club - NABA-SoTX
Native Plant Society of Texas - NPSOT
Travis Audubon Society - TAS
Texas Monarch Watch - Sponsored by TPWD
Caterpillar Identification - Tips on how to rear and ID caterpillars by Mike Quinn
Butterflies & Moths of North America - (Formerly USGS)
NABA International Butterfly Park - Butterfly park in Mission, Texas
Texas Entomology - Many entomology links compiled by Mike Quinn
Odonata Central - Dr. John Abbott's web site about dragonflies and damselflies (odonates)
Digital Dragonfly Museum - A site of Texas A&M