Perlmonks had a quick discussion on that issue.
Perl does not have massive CMS solutions to offer. The link in the previous node has many good examples though. Check out http://www.la-grange.net/cms#perl
I checked the WebGUI thing and was pretty good and I think it is suited for your job. You can create a small discussion board very easily through the admin interface.
If you need power over your site I would recommend Mason
And also, for every decent CMS you check out there should be a page with sites that are using it. WebGUI has a good list too.