It is important to determine your criteria for evaluating the relevance of retrieved books, journal articles, and web resources. These can include:
Some additional websites with more information about evaluation of resources (especially Internet resources) include:
Evaluating Sources of Information
From the SDSU Library & Information Access. Provides an overview of evaluating both print and electronic resources.
Critically Analyzing Information Sources: Critical Appraisal and Analysis
From Cornell University's Olin and Uris Library.