find out where and how to find information, ask the right questions, know what information you need, read, understand, criticise it, assess whether it meets its needs, manage it and use it for his own training. Written on a clear and didactic tone, without being simplified, the aim of this book is to teach readers how to master key concepts in documentary methodology and thus gain independent access to information. Examples are most often taken from the field of exact and natural sciences. In addition to the bibliography, the reader will find, in the end, a glossary of the main terms of library and computer language and an English-French translation lexicon. A website complements the book and provides links classified in chapter by chapter. This 2th, updated edition is enriched with 3 new chapters. In particular, a first develops a methodology for drafting the documentary question. The second deals with the fantastic progress of open publication, while the third attempts to answer the main questions on copyright and existing EU and national laws to protect these rights. This book will be of interest to all university and non-university, scientific and technical students, who face a need for information and the need to learn to train. 2th edition, preface by Sylvie Chevillotte, Elisabeth Noël