1. Use multiple words rather than single keywords
2. Put phrases in quotation marks to narrow search results. For example, if you were searching on George Washington, you should put this phrase in quotes otherwise you will get hits relating to anyone named George who lives in Washington.
3. Truncate your word and use an asterisk after it to pick up all forms of the word. For example, using the search term, librar*, would expand the search to include the terms, library, libraries, librarian, librarians, library's librarian's, etc.
4. Use AND, OR or NOT, also called Boolean operators, to help narrow your hits
a, about, an, and, are, as, at, be, by, from, how, I, in, is, it, of, on, or, that, the, this, to, we, what, when, where, which, with, etc.
Searching for information using just a top level domain
Use Google Advanced Search or type your search term followed by a colon and the domain suffix (for example -cat:.edu)
.edu educational institution
.com commercial institution
.mobi mobile device
.us, .ca, etc by country