The 1940 US census in digital format (non-indexed) will be available publicly on April 2, 2012 at 9AM EDT
You can volunteer to create an index at: http://the1940census.com


You can make a difference by volunteering at one of these other sites to transcribe the census. A big thanks to Archives.com , FindMyPast.com  and FamilySearch.org for collaborating to produce the always-free every name index.

How to Access the 1940 Census in One Step by the One-Step Tools webmaster Steve Morse and friends

Interesting Facts about the 1940 Census:
http://www.census.gov/newsroom/releases/archives/facts_for_features_special_editions/cb12-ffse01.html

Census Bureau Training Videos for the 1940 Census
http://www.archives.gov/research/census/1940/videos.html

Census Questions through the years:
http://www.census.gov/history/www/through_the_decades/index_of_questions/

Measuring America. The Decennial Censuses From 1790 to 2000 (downloadable.pdf)
http://www.census.gov/prod/2002pubs/pol02marv-pt2.pdf

General Tips for Genealogy Research in the US Censuses:
http://www.nypl.org/blog/2011/12/08/everyone-counts-using-census-genealogy-research

National Archives Tools for Finding Enumeration Districts:
http://www.archives.gov/research/census/1940/start-research.html

Omaha Public Library Genealogy Guide:
http://guides.omahalibrary.org/genealogy
 

Woodbury County, Iowa, USA. Click here for the Home page.