Sears and Moody identified various search strategies in their book, Using Government Publications: Electronic and Print.
Known Item Search: Useful when you know the title of the item you are seeking, for example Hearing on Appalachia : poverty alleviation strategies : hearing before the Select Committee on Hunger.
Subject searches: are similar in approach whether searching for government information or other library resources. Bibliographies, guides, indexes, and search engines are useful. There are a variety of special government publication
indexes and locators.
Agency Search: Most kinds of government information are not cited by the author but by the agency responsible for issuing them. One strategy is to identify the government agency responsible for publishing the information you want. For instance if you wanted a crop report you could go to the USDA website.
Statistical Search: The government issues a huge amount of data and if you're looking for numbers, a government source is frequently available. In a statistical search you will need to define in detail what you need--do you want crime data by race or other demographic characteristics? Do you need statistics at the city or national level? Do you need statistics for 1910 or 2010?
Special techniques searches: Include a number of complex, multistep search strategies employed when you want to locate a special topic or type of material such as material at the National Archives, historical information, legislative histories, regulations, grants, treaties, or patents.
How to identify and find government agencies:
The Agency Approach to Finding Government Information demonstrates a Three-Step "Agency Approach" to finding government information on the Internet.
First: Identify which government agency would be likely to publish the type of information you are looking for.
Second: Go to that agency's Web home page.
Third: Mine that agency's Web pages for information you are looking for.