As an alternative to perl-mode, there's also cperl-mode, which most people prefer and is I think also better maintained. There should be a cperl-mode in your emacs installation, but if you want more up-to-date/expermental versions, see the cperl-mode page on emacswiki.

Also: don't forget to switch on flymake-mode. It's one of the most useful tools in emacs, not just for perl:

;; Use cperl-mode for perl
(add-to-list 'auto-mode-alist '("\\.\\([pP][Llm]\\|al\\)\\'" . cperl-m
+ode))
(add-to-list 'interpreter-mode-alist '("perl" . cperl-mode))
(add-to-list 'interpreter-mode-alist '("perl5" . cperl-mode))
(add-to-list 'interpreter-mode-alist '("miniperl" . cperl-mode))

(add-hook 'cperl-mode-hook
  (lambda ()
    (require 'flymake)
    (flymake-mode 1) ;; use flymake
    (local-set-key (kbd "C-h f") 'cperl-perldoc))) ;; use perldoc inst
+ead of info on C-h f
[download]

You might also be interesed in Sepia and other stuff that turns up on CPAN