The underground (literally), perhaps less scholarly version of its sister store (Seminary Co-op Bookstore), 57th Street Books has been a neighborhood treasure for over 30 years – and the rooms with cookbooks, travel guides, mysteries, and science fiction just keep unspooling, with five in all, including a cheerful children’s section. The staff recommendations, some of them hand-written, are spot-on, and there’s a full calendar of author events. If they don’t have the book you want, they’re happy to order it.