This introductory text provides an overview of the processes and procedures associated with developing, maintaining, and evaluating a library collection at the building level. The processes and procedures practiced in school library media centers are discussed in relation to educational theory and principles of collection development. The text was revised in this third edition to reflect the philosophy and goals articulated in the American Association of School Librarians and the Association for Educational Communications and Technology's publication "Information Power: Building Partnerships for Learning" (1998). The book is divided into three parts. Part 1 examines the media collection in relation to its educational setting and discusses general principles of collection development. This part of the book establishes the environmental framework that is the collection's external tie to educational and informational systems and its internal relationship to the media program. Part 2 moves from the theoretical aspects of Part 1 to the practical considerations of materials selection. Part 3 describes the operations involved in developing and managing a collection. Lists of recommended readings and electronic resources point readers to in-depth coverage of many of the processes and techniques the book describes. Appendixes provide the following: agencies and associations that provide information and services to media specialists; an annotated bibliography of resources; and reprinted statements about intellectual freedom. Includes 13 tables and 20 figures. Includes an index. (Contains 40 references.) (AEF)