Christoper Peters, from Webjunction.org, has written an exceptionally detailed article about how to use Windows SteadyState on your library's public access computers ranging from installation to SteadyState features and how they can be optimized in a shared access environment.
The link above no longer works. Here's a new link to the article: http://data.webjunction.org/c/document_library/get_file?folderId=450505&name=DLFE-13562.pdf