The 1940 Census images will become available at 9:00 am 2 April 2012 at http://1940census.archives.gov. The census will not be indexed when it is released. Ancestry will be working with indexers around the world to complete the index as quickly as possible for their subscribers. FamilySearch.org has organized a volunteer 1940 Census Indexing Project with genealogy societies across the United States, and will post the index on its website as each state is completed.
What can you do to prepare for the census? Go to http://www.archives.gov/research/census/1940/ and become familiar with the “Questions Asked on the 1940 Census.”
Make a list of everyone you want to research in the 1940 census and their address. Find them in the 1930 census and, if the address is the same as it is in 1940, note the Enumeration District in the upper right-hand corner of the 1930 census.
Stephen P. Morse has provided a tool to convert census Enumeration Districts from 1930 to 1940 on his website at: http://stevemorse.org/census/unified.html
If you have any questions, visit the Heritage Library in March and we will be happy to help you find your ancestors in the 1930 Census and locate the ED where they will be listed in the 1940 Census.