A library can be a tremendous resource for teens—one that helps them to learn about themselves and the world they live in. But teenagers are intrinsically different from children and from adults, and these critical developmental differences affect the ways they interact with others, both in the world at large and in the library. Serving teens effectively in the library requires a basic understanding of who teens are and the developmental tasks they face—factors that affect all aspects of library service, from the specific programs and services we offer to the ways that staff provide assistance to the teen who is seeking help at a library service desk. This book enables library workers to better understand adolescent development, which allows them to provide a positive library experience for teens. Readers will learn how to supply excellent library services with and for teens, including in the areas of collection development, readers' advisory, reference and homework help, programming, and advocacy. The book identifies the best ways to have positive interactions with teens in the library based on their mental development and details best practices for teen services. The concluding section discusses advocating for teens, with emphasis on their right to privacy and equal access to materials and services.