Quotation Marks - put your search term or phrase in quotation marks and Google gives results for sites with that exact word list in that order either in the title or the body of the site.
OR or AND - in all caps between two search terms and Google gives results for sites that have either or both search terms expanding your search results.
Minus Sign - using the "-" before a word eliminates all results with your search term in the title or body of the site.
SITE: - followed by a trusted website and your search term targets results within that website only.
SITE:.gov or SITE:.ca - You can also follow SITE: with a top-level domain code (.edu, .gov, etc.) or a two-letter country code (.us, .cam, etc.) before your search term to get search results only with in that top-level domain or country.
intext: - locates results with your terms in the body of a site.
intitle: - locates results with your terms in the title of the site.
after: or before: - combine either of these with your search terms and dates you choose in this format yyyy-mm-dd to limit search results.