While it is important to evaluate information from all sources, remember the world wide web is not regulated. Anyone can post anything on the internet.
Accuracy- is this source correct? how do you know for sure?
Authority- who created the document? what credentials does she have?
Currency- is this information new or is it older? why might that matter for your project?
Objectivity- is there apparent bias in this source? if so, what is the author's agenda?
Scope- how much information about the subject are you getting? is there "conspicuously absent" information here?
More about evaluation.