Learn regexes. That's why you want to learn perl right? All those chainsaws for munging your dna? That's why I wanted to learn perl, at least at first. (Then I saw other possibilities and there was *really* no turning back... but that's another story. :) )

So, treat perl like the control panel behind the most powerful text manipulation toolset on earth. :)

How to learn regexes? Start using them. Perl one liners. Perlretut, in the perl documentation. In my case, it helped also to have some pretty gui tools to learn this stuff. Regex coach is free, and awesome. Editpad is not too expensive, awesome for regex find and replace. Also comes with a very good intro to PCRE (perl compatible regular expressions) tutorial, included in the documentation, and free online. Emacs is free, awesome for regex find and replace, but not as user friendly as editpad in my opinion (so I still haven't really learned how to use it, though it's on the to do list).

Make regexes your friends. The rest of perl will come naturally.