This guide is designed to introduce potential users of the California Language Census data to a means of accessing that data using an online, interactive computer system known as "1981 LC." The language census is an actual count of the numbers of pupils with a primary language other than English in California public schools as of March 1 of each year. The primary objective of the database is to improve the ability of the California State Department of Education (CSDE) to respond to management and research needs for information about pupils and staff in bilingual education programs. Five sections present (1) an overview of the process of conducting the Annual Language Census--language determination, proficiency assessment and counting/reporting; (2) an introduction to the database and an illustration of its use through a hypothetical, typical online session; (3) a description of the various methods for searching the database and for displaying the search results; (4) a description of potential database uses, including examples of searches which might be used in conducting the everyday business of the CSDE; and (5) the details of the database elements and structure, which are the same as those seen throughout the 1981 LC online EXPLAIN facility. Users of this database should have at least a novice-level experience with the WYLBUR text-editor and the SPIRES information retrieval language, as implemented at the Stanford Center for Information Technology. (LMM)