The document explains geographic concepts, products, and programs developed by the Census Bureau to assist users in analyzing census data for geographic areas. Emphasis is on small-area data such as census tracts, city blocks, minor civil divisions, incorporated places, congressional districts, and wards. Also presented are data for larger units including the United States, states and outlying areas, counties, and county equivalents. Types of data reviewed include outline maps, data display maps, geographic code schemes, reference files, and geography reference reports. Information is also presented on types of canvassing used in the 1970 census and on a technique called Dual Independent Map Encoding (DIME) developed after the 1970 census to transcribe geographic information so that it can be read and manipulated by computer. Maps, illustrations, and figures are presented for geographic areas of various sizes, census tract outlines, geographic identification code schemes, city reference files, and contents of a DIME-file record. The document concludes with an appendix presenting descriptions of areas associated with the 1970 census of population and housing and with the 1972 economic census. Also included is a directory of maps and files available from the Census Bureau. (DB)