PreS-Gr 3 A delightful beginning concept book on libraries that gives a basic introduction to history, types, organization and services in a colorful, entertaining manner. The illustrations depict people of all ages, from all walks of life, enjoying many aspects of the library. The text shows thoughtful organization and method encompassing maximum information in minimum wording. The only confusing note appears when describing the Library of Congress: ``Most books published in this country are kept there,'' when, in actuality, a copy of most books published is kept there. Gibbons provides a solid base for spinoff discussions, making the book useful as an introduction to library skills and for discussion in story hours. Written from a different viewpoint from Rockwell's I Like the Library (Dutton, 1977) and Numeroff's Beatrice Doesn't Want To (Watts, 1981), Check It Out! offers an upbeat, positive image that shows libraries as busy, interesting places. Marguerite Lewis, Glenmont Elementary School, N.Y.