Current Perl documentation can be found at perldoc.perl.org.
Here is our local, out-dated (pre-5.6) version:
the perltoot manpage (distributed with 5.004 or later) is a good place to start. Also, the perlobj manpage, the perlref manpage, and the perlmod manpage are useful references, while the perlbot manpage has some excellent tips and tricks.