If you go with Win32::GUI (which will give you a native (good), non-cross-platform (bad) Windows UI) you may want to get the PPM instead of the source. It is available here:
http://dada.perl.it/PPM/

In that case the docs are available at CPAN or at the home page at SourceForge:
http://sourceforge.net/projects/perl-win32-gui

There is an active support mailing list. This is the archive:
http://www.geocrawler.com/lists/3/SourceForge/8381/0/

Happy hacking,

/J