The perldoc.perl.org contains the official documentation from the Perl distribution(s). Here are some direct links which may be of interest.
Perl modules come with their own documentation. This includes modules installed from CPAN. On Unix-like (including Linux and Mac OS X) systems, you can access the documentation (for installed modules) with the
For example, to get the documentation for IO::File, enter
The Perl FAQ
Perl FAQs are available as part of your Perl distribution with the
Mailing List Archives
Perl-related mail lists are archived in several places.