Unicode is not an area that I have had occasion to delve into in any great depth. But I have read a few resources on the subject and can recommend them as a good place to start.

You can start with perluniintro from the perldocs. I think it was introduced with Perl version 5.8.0, so you'll have to look at a recent release of Perl to find that POD. perluniintro seems to be a user-friendly introduction to Unicode as it pertains to Perl.

Once you've digested that, you can go straight to the meat and potatos: perlunicode, also from the perldocs.

As for modules, there are a plethora of them on CPAN. However, Unicode support is native to Perl in the more recent releases such as 5.8.0. You don't need a module to take advantage of the built-in support. However, as always, the modules on CPAN may serve to make your life easier as you identify specific needs. A quick search of http://search.cpan.org for unicode turned up a number of them under the Unicode:: namespace. Scan through the PODs for those modules and you'll have a pretty good idea of whether any of them might be of use to your endeavor.

The official unicode home page is http://www.unicode.org. It has a lot of good articles on using unicode encoding.

Good luck!