When searching Google use these terms with your search words for better results:
Site:.gov Searches all .gov sites
If you know the agencey website, you can include part of the ura. Example" site:.cdc.gov
Site:.nd.gov Searches North Dakota sites
Use the Advanced Search option and select Government Documents
The Superintendent of Documents (SuDoc) classification number begins with a capital letter or letters representing a government department or agency. (A - Agriculture Dept., C - Commerce Dept., ED - Education Dept., etc.)
The numbers that follow these letters represent the office of a particular department. For instance, all Bureau of Indian Affairs publications will be given a number beginning with I 20. The numbers after the decimal point represent second and subsequent level offices.
Numbers immediately following the colon indicate numbered series, volumes or dates (the government documents are the only items in the library that will have : in the call number). Letters and numbers immediately following the colon are based on a system which organizes materials alphabetically by subject.
In general, documents are shelved in alphabetical and numerical order.
C 3.24/8: IN 23
C 3.25: AF 48
NAS 1.2: FR 76
NS 5: 100
This is not a decimal system. Numbers between punctuation are treated as individual whole numbers.
D 1.2: EX 83
D 1.16: TO 75
D 1.23: NA 42
D 1.23/2: CR 76
D 1.23/2-3: AL 23
D 1.23/2-11: LI 45
D 1.142: LE 78
Numbers precede letters.
C 61.12: 89-7
C 61.12: AM 32
Agriculture/ USDA. This will include the Forest Service, soil surveys, extention service and the Census of Agriculture.
National Archives and Records Administration. The National Archives has the Papers of the Presidents and the Federal Register.
The Department of Defense. This section includes the Army, Air Force and Navy. There are also large series of military histories, technical manuals, and reports. Materials from before the establishment of the Department of Defense in 1945 will be under W (War Department) and N (Navy).
The Department of Energy.
Environmental protection Agency
Fine Arts Commission
Farm Credit Administration
Federal Housing Financing Board
Federal Reserve System Board of Governors
Federal Trade Commission
Foreign-Trade Zones Board
Health and Human Services Department
Housing and Urban Development Department
Homeland Security, includes ICE, FEMA.
Interior Department, includes the Bureau of Indian Affairs, Bureau of Land Management, and the US Geological Survey
Interstate Commerce Commission, includes information on railroads.
US Agency for International Development
International Trade Commission
This is an old catagory for military materials.
National Aeronautics and Space Administration- we only have a limited collection of physical publications and access to a jarge database of materials.
National Capital Planning Commission
National Credit Union Administration
National Foundation on the Arts and the Humanities
Overseas Private Investment Corporation
Railroad Retirement Board
Veterans Affairs Department
War department. For more recent military publications look under D.