If you subscribe to the cpan-update daily digest, you get a single piece of mail every day that shows you a listing of recently updated modules. You won't have the time or energy to read through it carefully every day, but if you skim through it now and then, you'll see something that catches your attention. There's no guarantee of quality or popularity, but at least you know it's a module that's under active development.
If you haven't read it yet, you should look at The Perl Cookbook. It's Second edition is only a little dated
at this point, and it frequently recommends good and useful modules for particular tasks. Similarly Perl Best Practices has a lot of advice like that (though you should forget about Class::Std, and if someone tries to tell you about a great replacement for Getopt::Long, you should remind yourself that you have real work to do).
Also, these days, I tend to recommend perlsphere if you want to keep up with miscellanious developments in the perl world... it's a pretty comprehensive aggregator.
Update: corrected perlsphere URL.