There are various attempts to modernize Perl development. CPAN has a lot of older code, but a lot of newer code too. Sometimes it can be hard to know what the best-practices are, when there's so much inertia behind using the old modules.

Projects that have a long list of recommended modules are highlighted like this.

Perl 6
stuff in Perl 5
- Modern Perl, the book
  - (Modern Perl, the book), the blog
- the Enlightened Perl Organization
- perlbuzz.com (on reddit)
- O'Reilly's "Perl Best Practices"
- perl5i

for recommendations of specific CPAN modules, see here