Review of: Fabio Metitieri – Riccardo Ridi, "Biblioteche in Rete : istruzioni per l'uso". This updated version of the famous "Ricerche bibliografiche in Internet", after the Introduction, is divided in three parts, which have articulated chapters: I. Concepts and tools: 1. Bibliographic searches, 2. Information retrieval: tools and strategies, 3. Opac and virtual library; II. Libraries and Opacs in Italy and in the world: 4. Libraries and Opacs in the world, 5. Libraries and Opacs in Italy, 6. European libraries and Opacs, 7. United States Libraries and Opacs, 8. Specialized Opacs, archives and museums; III. Beyond catalogs; texts and databases: 9. Beyond catalogs: texts, 10. Databases: archives and host computers in Internet, 11. General meta-resources and information for librarians.