Minneapolis is a book lover's paradise. There are dozens of neighborhood bookstores, a sleek new $125 million Minneapolis Central Library, and Open Book, the nation's first facility devoted to the literary arts. No wonder it was dubbed America's most literate city last year. But one of the best-kept secrets is that Minneapolis and nearby Mankato have evolved over the past 75 years into major publishing hubs for the school and public library market. Of the estimated 40 publishers that serve the school and library market in this country, eight are in Minneapolis and four are in Mankato, including three of the nation's largest independently-owned children's book publishers. ABDO Publishing Group, Capstone Publishing Group, and Lerner Publishing Group--all of which are family owned and operated--supplied more than 1,600 of the approximately 2,350 titles released last year by Minnesota publishers for the school and library market.