One Step site by Steve Morse to review his 1940 finding aids and tutorial.
Steve has short tutorial quiz (don't worry, there are no wrong answers) to help you begin thinking about where you should be looking by Enumeration District. In addition to the tutorial, you will find a 1940 ED finding tool as well as a 1930 to 1940 ED conversion utility. If you are lucky and your people stayed put between 1930 and 1940, the conversion utility may be all you need to get you on your way.
If you are eagerly awaiting the release of the 1940 census, prepare now and be ready to hit the ground running on April 2nd. Now, let's hope the servers can handle the traffic! :)