Google and the academic databases to which the Library subscribes share some search strategies in common, while Google also has some that are unique. Use these tips to make Google work better for you.
four *, seven years ago
potato site:nytimes = Posts from the NY Times that mention Afghanistan
potato –site:wikipedia.org = Results about potatoes but NOT any from wikipedia.org
potato site:*.gov = Results about potatoes from government sites/agencies
potato info:fda.gov filetype:pdf
Here's a short introduction to how it works (though with the very positive attitude you'd expect from a company talking about itself and not a lot of reflection).