Well, I have Butterflies Through Binoculars the West...I'm pretty sure there's another one for "the East"(you're in the East, I see). The great thing about it is that it has little maps for each species, showing where they are know to be found and how many "broods" in what areas. Two broods would mean the butterflies lay eggs and the butterflies from the eggs would lay eggs again that same year, for example. There's also distinguishing markings pointed out on butterflies likely to be confused with other species. I also have a Peterson's field guide (I seem to have misplaced it right now) and a Field Guide to Butterflies by the National Audubon Society. Both good, but I just prefer the Butterflies Through Binoculars books the best.