Items are added to the library selectively so when you discover something via a Google search, be selective.  When evaluating a web site look for these attributes:

1. Purpose : Is it there to inform? Persuade? Sell? Entertain?
2. Authorship & Authority : What are the person's (group's) credentials? Can you tell? Is the person/group credible? An authority?
3. Objectivity : Does the site have a bias? Can you articulate what it is?
4. Accuracy : Are sources cited or acknowledged?
5. Currency : How current is the information? Is this important?
6. Completeness : Is the information complete or just a summary of information found elsewhere?

Where possible look for additional sources of information to verify information you find on the web, particularly if your are unsure about its authority, accuracy, and currency.  Consider limiting your google searches to .edu and .gov sites.