Consider these criteria when selecting sources. Make sure you choose a source that is credible, objective, and thorough.
When was it written? Is it recent enough to be relevant?
For whom was it written? Is it too complex or too simple?
Approved by other experts? A scholarly source?
Well written? Does it use good spelling and grammar?
Is he or she an expert? What is his or her background, education, etc.
Does the author intend to inform or persuade the reader? What is the goal of the source?
Is the scope of the source appropriate? Does it match your topic?
How long has the publisher been in business? Are they highly ranked?
Is the author presenting information or drawing conclusions for you? Is the language neutral or emotional?
Does the source present multiple sides of an issue? Does the author have an agenda?