My only reference besides the Internet was a book called Fossils of Ohio, Bulletin 70 from State of Ohio, Department of Natural Resources, Division of Geological Survey. While covering the state of Ohio, their geology is similar to that of Indiana and Kentucky so the information applicable. It does have its limits since it has to cover so much information for such a large state. I bought this book from the Falls of the Ohio State Park gift shop (when they still had one) years ago.
I just acquired this week and last, two more books that should help me with creating better entries on the fossils I try to identify.The next book is Index Fossils of North America by Hervey W. Shimer and Robert R. Shrock from MIT Press. This book is nice though dated (1944). It has a lot of images to study and compare to specimens.
The last book is one I became familiar with in the Indiana University Southeast library while I was a student there. It is Memoir 93 Silurian and Devonian Corals of the Falls of the Ohio by Erwin C. Stumm, The Geological Society of America. Most of the fossils I find in Jefferson County near the Ohio River and over in southern Indiana tend to be corals. This book is a great asset to help with the study of those corals. The book I recently purchased was in excellent condition as if it was never used since it was published in 1964.
Other resources are Dry Dredgers website for Ordovician fossils, Kentucky Paleontological Society (KPS) website for Kentucky fossils and older books whose copyrights have expired. Another good reference to consult is the JSTOR database at the library for journal papers. It is a great research tool for showing how papers reference other research and how they are in turn referenced by later works.