This is one of the first (with I Know a Policeman, below) in a new series ""designed to introduce young children to community helpers and familiarize them with the functions of civic service groups."" Andy's acquaintance with the librarian is only incidental to his acquaintance with the library, its procedures and functions. He gets a library card, becomes familiar with the charging system, and learns how books are catalogued and classified; he listens to a lecture on the importance of books and libraries and watches library workers. The attention to specifics is both an asset and a handicap; by focusing on one charging system rather than on the principles of circulation, on the subject heading for a particular title which might be designated differently, she increases relevance for some children at the expense of confusion for others. It's a sturdy, not unattractive introduction to the public library for second graders before the first class visit--especially if your local library uses Gaylord machines and catalogs McClung's Tiger under Swallowtail Butterfly.