Before using the information found, you have to assess its quality and relevancy:
Be aware that Google use algorithms (PageRank) to filter, or tailor, the search results, based on previous searches you have done – the sites you have viewed, what you clicked on and other data that can be gathered from your browser. So the exact same search, using exactly the same search words, can return different results for different individuals.
Pariser, Eli. "Beware online filter bubbles." Filmed February 2011 in Stockholm, Sweden. TED video, 8:47.