Hey, my name is Stephanie too!
Anyway, we basically just looked at gardening books and at our local garden center and picked out plants listed as buterfly magnets. Almost all of them thrive in full sun.
We have several buddleia in different varieties, and all look lovely and smell nice but the butterflies prefer the Honeycomb variety. That bush is literally covered with butterflies from dawn to dusk!
Bee Balm really draws hummingbirds (and bees) and is a really cool plant!
Anise Hyssop (we have two varieties) is another butterfly fave.
We probably have 40-50 plants out there, but I'll try to remember some more...several varieties of coreopsis, vervain, echinacea, sedum, great blue lobelia, ruby slippers lobelia, garden phlox, babies breath, prairie mallow, false mallow, lavatera, yarrow (several varieties), penstemon, asters, jacobs ladder, bachelor's buttons, caryopteris (great for late season bloom), salvia.
It's also important to have a shallow water source for the butterflies. We have a large saucer (to go under a planter ) that we lined with gravel and cover the gravel with water so the butterflies have a place to land and drink. The birds like it too!
If you try it, please let me know how it goes!