Planning is, in principle, a theory, but its existence is justified only as a tool for practice. In this study we start from the concept of documentary center, used as a common name for libraries (encompassed herein in its broad and diverse typology), documentation centers and information centers. In the first part of this paper the theoretical aspects related to the planning, organization and implementation of the aforementioned documentary centers theoretical approach that is continually reinforced by a large number of practical examples are discussed. The planning is studied as a means for application to all that pertains to staff, collection of materials, the building and facilities, budget and financing, as well as márquetin and dissemination of services provided. The second part addresses, now globally, all these aspects related to facilities such as public libraries, school and university, documentation centers and information centers. The overall objective of the work is, in short, get a planning study in which the theoretical approach appears fully endorsed by the concrete study of a large, diverse cases and, in any case, essentially practical, useful for students and for all professionals documentary centers, will find here a suitable tool for effective update regarding some issues, such planning, which are increasingly important.