Current Perl documentation can be found at perldoc.perl.org.
Here is our local, out-dated (pre-5.6) version:
Since Emacs version 19 patchlevel 22 or so, there have been both a perl-mode.el and support for the perl debugger built in. These should come with the standard Emacs 19 distribution.
In the perl source directory, you'll find a directory called ``emacs'', which contains a cperl-mode that color-codes keywords, provides context-sensitive help, and other nifty things.
Note that the perl-mode of emacs will have fits with
(single quote), and mess up the indentation and hilighting. You should be
"main::foo" in new Perl code anyway, so this shouldn't be an issue.