There are too many informative websites to list, so I'll attach a link to just one Google search (how to raise butterflies). You can also do searches for the butterfly and moth species that are native to your specific location, and the very important facts about time of year, disease and parasite prevention, etc.

Once you've chosen the species that you wish to raise and release, then you can learn about which host plants to grow

There is a Butterfly Gardening Forum in the GardenWeb. You could spend hours in there just reading old threads about the trials, tribulations, and successes of their endeavors. There are lots of very helpful people over there.

HERE'S THAT LINK I PROMISED just to get you started on your research.