Through the NARA(Nat'l Archives,) the 1940 census is accessible free to anyone. They tell you how to go about looking for family, step by step. Since it is not indexed all of us have to go page by page in the city/state of interest. This is not a easy task. I was looking for one family group, was following them and they had moved to Ga. While looking for this group and any surname of family, I stumbled on surnames of family. You just have to be patient and look for street names in the ED.'s.
Familysearch.org may also be helpful in finding family surnames to look for in 1930 and 1940.
By the time the 1940 is indexed, I know many of us will have pulled out all of our hair .