Guides are intended to suggest where to go for further information. Current guides are important to find, as they will provide up-to-date information. Even a dated guide can be helpful in getting the researcher into sources in areas not familiar to him.
Guides are usually organized by types of literature with key resources being listed. Discussions of search techniques, trends within a discipline and summaries of new information technology changes are found in this resource type. An information guide is an excellent place to consult when starting research in an area new to you. A variation on a guide to literature is a Webliography or a web-based bibliography. Guides and bibliographies of bibliographies are 3° literature sources.