This tutorial is a thorough and deep introduction to the Digital Libraries (DL) field, providing a firm foundation: covering key concepts and terminology, as well as services, systems, technologies, methods, standards, projects, issues, and practices. It introduces and builds upon a firm theoretical foundation (starting with the `5S’ set of intuitive aspects: Streams, Structures, Spaces, Scenarios, Societies), giving careful definitions and explanations of all the key parts of a `minimal digital library’, and expanding from that basis to cover key DL issues. Illustrations come from a set of case studies, including from multiple current projects. Attendees will be exposed to four Morgan and Claypool books that elaborate on 5S, published 2012-2014. Complementing the coverage of `5S’ will be an overview of key aspects of the DELOS Reference Model and DL.org activities. Further, use of a Hadoop cluster supporting big data DLs will be described.