An Index of Books by Genre
This site is administered by Janet Kerns, a retired Librarian based in Oklahoma, on behalf of a "small but devoted team of current and former Librarians in various parts of the United States." I spent some time trolling around the "genre" list and found some authors that I will definitely be reading. A good place to expand your author repertoire.
The main page gives you the opportunity to input an author and then browse the categories that are connected to him/her.