Lots of good reading on plover.com. Back in my Perl days he was one of my favorite writers. He's also the only person who does a clear job of explaining how regular expressions work.
Higher Order Perl is a must read for anyone working in any mainstream dynamic language (Python, Ruby, JavaScript, etc.). There are efforts afoot to port the examples to various other languages, much the way The Little Schemer has been ported and mangled in various ways. It's just a really enlightening book for anyone without a strong functional programming background (and probably even those with a lot of functional programming experience, as it happily bounces back and forth between functional idioms and Perl idioms to produce really interesting code).
It's one of a few books that I've checked out of the library a couple of times, only to end up buying it. (Last time I moved, I had something like 30 boxes of books...I sold more than half of them to Half Price Books, and promised myself that I do not buy books anymore. But some books are just mandatory.)
