National Standards and Resources:
The office of the Secretary of the Interior publishes Standards and Guidelines, including ones for : Architectural and Engineering Documentation; Rehabilitation of Properties; Preserving, Rehabilitating, Restoring, and Reconstructing Historic Buildings; Treatment of Cultural Landscapes.
The Secretary of the Interior's office publishes Preservation Briefs, which give guidelines to owners of historic buildings on how to treat common problems affecting historic structures and materials.
In addition, the Secretary of the Interior's office provides a variety of guidelines on sustainability, tax incentives, and historic rehabilitation through its Technical Preservation Services.
Building Technology Heritage Library, available from the Internet Archive, is a catalog of primarily American and Canadian pre-1964 architectural trade catalogs, house plan books and technical building guides.
Library of Congress provides access to Historic American Building Survey/Historic American Engineering Record/Historic American Landscape Survey from 1933 to the present. This collections document achievements in architecture, engineering, and landscape design in the United States and its territories through a comprehensive range of building types, engineering technologies, and landscapes. Administered since 1933 through cooperative agreements with the National Park Service, the Library of Congress, and the private sector, ongoing programs of the National Park Service have recorded America's built environment in multiformat surveys comprising more than 556,900 measured drawings, large-format photographs, and written histories for more than 38,600 historic structures and sites dating from Pre-Columbian times to the twentieth century.
National Register of Historic Places – lists registered historic cultural resources by state.
Preservenet is a national network to provide preservationists with a comprehensive database of regularly updated internet resources and current professional opportunities.
California Office of Historic Preservation provides information on historic preservation ordinances, regulations, and incentive programs in the State of California.
California Historical Building Code, provided courtesy of the Office of the State Architect.
Los Angeles-Based Resources:
The listing of Historic Cultural Monuments in Los Angeles is accessible through the the City's Office of Historic Resources. Other cities, such as Pasadena, have their own listings.
Maps and descriptions of Historic Preservation Overlay Zones in Los Angles are accessible through the Office of Historic Resources.
The Los Angeles Conservancy provides some poibnters on researching historic properties in Los Angeles.