Make sure your search terms are spelled correctly.
Use multiple words
Using multiple words will return more refined results than a single word. For example, typing our free service will return more relevant results than typing just service. (Keep in mind that relevant results are returned even if they don't contain all query terms.)
Use similar words
The more similar words you use in a search, the more relevant your results will be.
Use appropriate capitalization
Capitalize proper nouns, and remember that lower-case words will match any case. For example, typing search will return all documents containing the words search, Search, and SEARCH. Typing Search, however, will instruct the search engine to look only for the capitalized word.
Use quotation marks
Use quotation marks to find words which must appear adjacent to each other, for example, "our pledge to you." Otherwise, the search results will include the word our, pledge, to, and the word you, but not necessarily in that order. The words may appear anywhere, and in any order, within the document.
Use plus (+) or minus (-)
Use a plus sign when your search term or phrase must appear in the search results. Use a minus sign to indicate undesirable term(s). The plus sign tells the search engine that a certain word or phrase is required in the search results, and a minus sign indicates that a word or phrase must be absent in the search results.
Note: A phrase must be contained within quotation marks. Leave no spaces between the plus or minus sign and the term.
Wildcard searches can expand the number of matches for a particular request. The * character is used as the wildcard character.
For instance, searching for wh* will find the words what, why, when, whether, and any other word that starts with wh.
Searching for *her* will find the words here, whether, together, gathering, and any other word that contains her anywhere in the word.
Wildcards may be combined with the standard plus (+) and minus (-) modifiers, quotes for phrases, as well as the field search specifiers.
+wh* -se*ch will find all pages which have a word that starts with wh and which does not contain a word that starts with se and ends with ch. "wh* are" will find the phrases where are, what are, why are, etc.