To begin with, searches, primarily using 'Google' search engine were carried out with the search terms '1950s' or 'postwar' or 'post-WWII' and 'culture'.  Directories, such as 'Yahoo', brought up a few new sites but I found that the range and quantity of sites listed did not approach those which could be found through other methods.

The above methods did not yield sites referring to a variety of cultural expressions to a satisfactory degree.  After being inspired by Daniel Belgrad's book 'Culture of Spontaneity' which uses this phrase to describe the alternate cultures of the 1950s, I included 'spontaneity' as a search term.  More specific searches were also undertaken with additional terms such as 'jazz'', 'beatnick / beatnik'  and 'Cold War'. (as necessary) Therefore some of the searching has been undertaken in a somewhat specific manner, but this is appropriate to  the aim and the choices of categories was reflected by the other material, websites, and internet resource pages found.

Key sites had some excellent internet resource pages, which were often found to be more helpful than using search engines, since the sites had been previously reviewed and categorised.  These built on primary searches and enabled the 'web' of my search to expand significantly and rapidly, with a snowball effect as increasingly more links were followed.
 

Belgrad, Daniel, 'The Culture of Spontaneity: Improvisation and the Arts in Postwar America', University of Chicago Press, Chicago, 1998.