IBPA … a good place to start
I took a trip over tot he IBPA website to search out their mailings to libraries since so many of the authors I’ve been working with are interested in library distribution.
I found a couple pages you might not know are there.
over the years http://www.ibpa-online.org/cooperative-marketing-mailings-direct-and-online/ which are not too expensive yet have a focus of distribution. And of course they have a listing of distributors you might contact who might connect to libraries. http://www.ibpa-online.org/resources/distributor-wholesalers/