While it is aimed, I think, more at the intermediate programmer, chromatic's freely downloadable Modern Perl might be a good beginners intro to Perl. And while I can't recommend Wikipedia as a beginners resource because it gets rather CS-ish rather quickly, all the topics davido mentioned and more are there and may serve as useful points of departure to more accessible on-line resources: array; linked list; binary tree; hash, or associative array; ...

And you are always welcome at The Monastery Gates.