Evaluation takes place in the context of your research task. What do you need? Are you browsing for new ideas and opinions or trying to find evidence to support a position? Always ask: Does this source provide the kind of information that I need?
Does the item contain information relevant to your topic?
Read the introduction and conclusion to the source.
Scan its headings or chapter titles.
Look through the tables of contents and indexes of books.
Does the information presented support or refute your ideas?
Do you have counter arguments for the information refuting your ideas?
Does the material provide you with new information?