University of Brighton Libraries . St Peter's House contains many relevant books and back-issues of many journals. The most useful I found was 'Art and Industry', a contemporary journal, which includes many articles about the posters produced during the war. http://prism.brighton.ac.uk/TalisPrism/browseResults.do?&expandedWorkID=0.0&browse_action=9057&rootRSetId=1265d06e27400000&browse_RootRSetId=1265d06e27400000&displayRowPath=0&pageSize=10&menuBarTag=search&displaySearchAsText=false&openRowPathSet=0:0A
Wow, I like the way this catalogue is set up, with the options to discover related information via a mind-map - I wonder how useful that actually is! I spent a lot of time in the Library at the University of Sussex, especially in the Mass-Observation Archives.