This text provides a comprehensive treatment of collaborative filtering and recommender systems, covering both theoretical and practical aspects. It fulfills the urgent need for a textbook that helps readers get quickly acquainted with the field, particularly the newest Web 2.0 and its applications. It provides sample code or software library for algorithms in the book and includes intensive support for course instructors, including chapter problems and exercises and a website with solutions. This text for advanced undergraduates and first-year postgraduates is also an ideal guidebook for practitioners working on information filtering, data mining algorithms, or Web 2.0 applications.