Choose Effective Keywords
Remember to think about the words you think will be in your desired results page. Determine the most important words in your search, as well as potential synonyms.
Case
Google is NOT case sensitive. There is no need to capitalize letters.
Use Multiple Keywords with "OR" There are many ways to state your search term or topic. Google's default behavior is to consider all the words in a search. If you are searching for [female], you might also consider using [girl] or [woman], as well. If you want to specifically allow either one of several words, you can use the OR operator (note that you have to type "OR" in ALL CAPS - otherwise, Google will ignore it). For example: global warming OR climate change.
Synonyms (~)
If you want to search not only for your search term but also for its synonyms, place the tilde sign (~) immediately in front of your search term.
Phrase Search (" ")
Use quotation marks to search for a phrase. Quotation marks glue words together; there can be additional words before or after the phrase, but the phrase will always stay together in the results. However, Google already uses the order and the fact that the words are together as a very strong signal and will stray from it only for a good reason, so quotation marks are usually unnecessary. By insisting on phrase search you might be missing good results accidentally. For example, a search for "George Bush" will miss pages that refer to George W. Bush.
Terms You Want to Exclude (-)
Using a hyphen immediately before a word tells Google that you do not want pages that contain this word to appear in your results. The hyphen should appear immediately before the word and should be preceded with a space. For example, the query [anti-virus -software] will search for the words 'anti-virus' but exclude references to software, whereas the query [anti-virus software], the hyphen will not be interpreted as an exclusion symbol. You can exclude as many words as you want by using a hyphen in front of each one.
Fill in the Blanks (*)
The *, or wildcard, is a little-known feature that can be very powerful. If you include * within a query, it tells Google to try to treat the asterisk as a placeholder for any unknown term (or terms) and then find the best matches. For example, the search [Google *] will give you results about many of Google's products, whereas the query [Obama voted * on the * bill] will provide results about different votes on different bills. Note that the * operator works only on whole words, not parts of words.
Search Exactly As Is (+)
Google employs synonyms automatically. For example, a search for [FL history] will bring back results for Florida history. However, Google sometimes helps out a little too much and gives you a synonym when you don't really want it. By using a plus sign (+) immediately before a word, Google will return results matching precisely what you typed. For example, to search for the satirical newspaper The Onion, use [+The Onion], not [+ The Onion].
Specify Number Ranges (..)
Specify that results contain numbers in a range by specifying two numbers, separated by two periods, with no spaces. For example, specify that you are searching in the price range $250 to $1000 using the number range specification $250..$1000.
Connect Two Words (_)
Connect two words together with the underscore (_) symbols. For example, the query [child_care] will find this pair of words either linked together (childcare) or connected by an underscore (child_care).
Search Within a Specific Website (site:)
Google allows you to specify that your search results must come from a given website. For example, the query [iraq site:nytimes.com] will return pages about Iraq but only from nytimes.com. The simpler queries [iraq nytimes.com] and [iraq New York Times] will usually be just as good, though they might return results from other sites that mention the New York Times. You can also specify a whole class of sites, for example, [iraq site:.gov] will return results only from a .gov domain and [iraq site:.iq] will return results only from Iraqi sites.
Search Within Results
A little known or used feature is Google is Search Within Results. When you get millions of hits from a search and you want to narrow it down, just go to the bottom of your results page, select Search Within Results, type in an additional word or phrase to make your results more specific, and you'll end up with fewer results to look through. For example, compare [Hawaii] to results within [big island].
Specialized Searches
Use the specialized searches. Most of them are right there above the search box and they can really save you time: Images, Video, News, Maps, and more. Selecting any of these will narrow down your search to just images, videos, etc. For more specialized searches and other features, see more Google Products.
Use the Search Tools
Search Tools will appear on your results page after you've searched. With them you can narrow down your search to maps, videos, books, social media, and much more. It's a great time saver.