Type of publication: Scholarly, peer-reviewed journal? Newspaper? Is it a book or a web site?
Author: Who is the author- are they an expert in this field? What else has he/she written? What are their credentials and profession? Can you detect a bias or point of view from the author?
Publisher: Government, university or commercial press? Is it a corporation, a government agency or a professional organization?
Audience: Who is this information intended for? Is this for the general public or people with a particular bias?
Publication date: How current is the information? When was it published/created?
Purpose: Was it written to inform, persuade, entertain or sell?
Usefulness and coverage: How is it relevant to your topic? Is it in-depth coverage, or only partial? Primary or secondary source? What kind of evidence is presented?
Links/reference/bibliography: Are they reliable? Do the links work? Is the bibliography comprehensive, appropriate, and/or sufficient?
Also helpful is UC Berkeley Library's great guide for evaluating web pages.