Google - If you are using Google as your search engine try Advanced Search.

You can limit your searches in several ways:   Search within a site or domain - type .edu Use flexible vocabulary - if one phrase or combination of words doesn't work, perhaps another will. Limit by Language, etc.

Google Search Tips (MIT Libraries)

BEWARE:  Always remember to evaluate the quality of the site you are viewing.  Don't believe everything you read unless the information comes from a reputable or reliable source.  

See Evaluating Web Pages: Techniques to Apply and Questions to Ask  (Univ. of California Berkeley Library) Consider authority, accuracy, objectivity, currency, and completeness as you evaluate whether to utilize the information found on a particular Web page.

Power Tips (Tech Insider) - Video (about 2 minutes)