Use a plus sign ( + ) before words which are absolutely critical to your search.

Use a minus sign ( - ) before words that you want to be excluded from the search. This is especially useful when searching for a surname with a common usage such as rice or one which is shared with a famous celebrity such as Jerry Rice (i.e. you would enter your search as rice-jerry to exclude results with the word 'jerry').

Use quotation marks ( " " ) around any two word or greater phrase to find results where the words appear together exactly as you have entered them. This is useful when searching for proper names (i.e. a search for george washington will bring up pages with george foreman and denzel washington, while searching for "George Washington" will only bring up pages with the name george washington included as a phrase.

Use OR to retrieve search results that match any one of a number of words. The default operation for Google is to return results that match ALL search terms, so by linking your terms with OR you can achieve a bit more flexibility (ie white genealogy OR geneology OR cemetery OR census OR ancestry OR website)