The International Computer and Information Literacy Study (ICILS) 2013, conducted by the International Association for the Evaluation of Educational Achievement (IEA), studied how students in different countries develop the knowledge, understanding, attitudes, dispositions, and skills that comprise computer and information literacy (CIL). The aim of ICILS 2013 was to report on student preparation and achievement by way of an authentic computer-based assessment, the first of its kind in international comparative research. The ICILS 2013 international report sets out the core findings of the study. The report documents variations across the participating countries in a wide range of different CIL-related outcomes, actions, and dispositions. It also describes the extent to which these outcomes were associated with various characteristics of the participating countries as well as with student characteristics and school contexts. This User Guide describes the organization, content, and use of the international database from a practical perspective. This User Guide also includes the following appendices: (1) International version of the ICILS 2013 questionnaires; (2) National adaptations of international questionnaires; (3) Variables derived from the survey data; and (4) ICILS 2013 sampling stratification information. [The Guide was prepared with contributions from: Clara Beyer, Diego Cortes, Sabine Meinck, and Plamen Mirazchiyski.]