After identifying and locating materials pertaining to a topic you'll want to evaluate their suitability and appropriateness for your research.
In analyzing print and electronic sources consider the following:

Author
What are the author's credentials or background, did the author write other works on the topic?

Date of Publication
When was the material published, has it been updated, is currency important for your topic?

Audience
Determine if the article or book is written for a scholarly or general audience. Is the audience level appropriate for your purposes?

Scope
Is this a general or specialized treatment of the topic; does it address your argument; does it cover the time period you're interested in?

Documentation
A bibliography and footnotes indicate the author has consulted other sources. The bibliography and notes may contain additional sources for you to consider.

Scholarly or Popular
Is the book/article written by scholars or journalists; is the journal "peer reviewed" by other scholars; does the author cite his/her documentation; is it written for other experts or a general audience?

Primary or Secondary Source
Historians work from original sources and the writings of other scholars. "Primary" sources include official documents, letters, diaries, speeches, and contemporary writings. "Secondary" sources include the books and articles written by scholars based on primary and other sources. Click Here for additional information.

Adapted from Critical Evaluation of Resources, UC Berkeley Library.