Selected Links for the Type Cincinnatian Series
The Dry Dredgers website includes information on the club's activities, as well as Jack Kallmeyer's crinoid identification site, Rich Fuchs' scolecodont identification site, Bill Heimbrock's trilobite fragment identifier, and Colin Sumrall's guides to edrioasteroids and weird echinoderms of the Cincinnatian. They've also recently added a bryozoan page.
The geological surveys of Ohio, Indiana, and Kentucky all offer information on Ordovician fossils and stratigraphy. The Kentucky survey has all of its 7 1/2' geologic quadrangles available online.