“The National Archives and Records Administration will open the 1940 U.S. Federal Census on April 2, 2012—the first time this collection will be made available to the public. Once we receive the census, we will begin uploading census images to our site so the public can browse them. Initially, this collection will be what we call a browse-only collection. This means a person can scroll through the pages of the census districts much like you would look at a microfilm or a book. At the same time, we will be working behind the scenes to create an index of the census that will eventually allow people to search for their family members by name as they currently can with all other censuses on Ancestry.com. Note also that the 1940 U.S. Federal Census will be accessible free of charge throughout 2012 on Ancestry.com.” The link to ancestry.com’s 1940 Census page is: http://www.ancestry.com/1940-census.
The digital images of the 1940 will appear on April 2nd, 2012 at 9 AM on this National Archives (NARA) web site: http://www.1940census.archives.gov/.
Another important web page on ancestry.com, which is essential for finding your family members, in 1940 is the U. S. Enumeration District Maps and Desciptions, 1940: http://search.ancestry.com/search/db.aspx?dbid=3028.
To initially find your relatives, you must know what Enumeration District in which they lived at enumeration time.