Evaluating the sources you find is an important part of conducting research. There are a number of methods useful in making this evaluation. These especially apply to sites on the open web.
The 5 Ws and H
Who is the author of publisher of the information? Do they have the credentials to prove the trustworthiness of the source?
What type of publication holds the information (book, peer reviewed journal, magazine, website)? Is it appropriate for research?
When was the information published? Is this important for your topic?
Where did the information come from? Are references provided? Can the information be checked someplace else?
Why is this information published? Is the author trying to persuade you? Is there obvious bias or objective?
How will this information be helpful to you? Is it relevant to your topic?
CRAAP test
Currency - Is currency important to your topic? Are any of these dates provided?
Creation date
Posting date
Revision date
Relevance - Does the information support your topic or answer your questions? Is the level of information appropriate for your audience (too simple - too technical)?
Accuracy - Is the information supported by evidence or is it peer-reviewed? Are sources cited? Is there a bibliography? Is it well-written? Can data be confirmed using other sources?
Authority - Who created the document or the web site? Are their credentials given?
Purpose - Who is the intended audience? Is there an obvious bias on the part of the creator? Does it present:
