This document provides an overview of the concepts and processes behind reference services and the most important sources consulted in answering common reference questions. The book is divided into two parts. Part 1 deals with concepts and theory. It covers ethical aspects of reference service, the reference interview, the principles and goals of library instruction, bibliographic control and search strategies, trends in electronic reference services, library instruction, staff training and development, an evaluation of reference services, the management of reference services, and reference services for special populations. Part 2 describes the general principles and sources for selecting and evaluating reference tools and the standards for building a reference collection. Sources include directories; almanacs, yearbooks, handbooks; bibliographic sources; dictionaries; encyclopedias; geographical sources; bibliographies and library catalogs; indexes and abstracts; and government documents and statistics. Notes, lists of sources and additional readings are included at the end of each chapter in part 2. Throughout the text, specific issues, concepts, and search strategies are highlighted. Author/title and subject indexes are also provided. (AEF)