I found Programming Perl a really good read, but a poor reference. In fact none of the Perl books that I have found seem to work as a reference for me. The far and away best reference I have is the "Perl Pocket Reference". I can find what I want in it quickly and it gives enough information to either answer the immediate question, or hints at the right jargon so I can then look in "Programming Perl" or perldocs for a fuller explanation.

It's also worth having a look through the Tutorials here for a leg up in getting to grips with Perl.

The main thing though is to look at the questions and answers in SoPW. You get exposed to a vast variety of different techniques at different levels and in different application domains. If you want to broarden your Perl knowledge, Seekers of Perl Wisdom is the place to do it.