This guide is designed to assist librarians in the selection, acquisition, and use of a core-reference collection. Section 1, "Sources," is an annotated bibliography which focuses on the selection of those works that should constitute the main reference holdings in a small library or a desk (ready-reference) collection in a larger library. Sources have been limited to 76 currently available works which are priced reasonably and judged to be of excellent quality. An additional 50 reference works are cited in 27 notes. Topics covered are: (1) General Works; (2) Biography; (3) Religion; (4) Language; (5) Literature; (6) Visual and Performing Arts; (7) History; (8) Statistics; (9) Political Science and the Law; (10) Geography; (11) Careers and Education; (12) Business; (13) Social Customs, Home Life, and Sports; and (14) Science and Technology. Section 2, "Priority Ratings of Sources," is designed to help small libraries in the acquisition process. The sources listed in the bibliography are divided into 10 groups, with 20 sources, such as almanacs and encyclopedias, arranged according to required frequency of purchase (e.g., annually, biennially). The remaining 59 works are arranged in their order of importance. Section 3, "Reference Works Exercises," is intended for library workers new to the reference staff or more experienced workers who wish to review the use of basic reference tools. Nine exercises, each with an informative introduction, require the use of a variety of reference sources. The guide is indexed by title and subject. (KM)