Michael, I think the #1 book to get for macrolichens of that area is the Macrolichens of New England. Excellent resource.
For an up-to-date treatment for the southern Appalachians that includes crusts, see Lendemer, J.C., R.C. Harris and E.A. Tripp. 2013. The lichens and allied fungi of Great Smoky Mountains National Park: an annotated checklist with comprehensive keys. Memoirs of The New York Botanical Garden 104: i-viii, 1-152.
Bruce