The Camel, the real Bible of Perl.
The Llama, the standard Perl tutorial
Now in its 2nd edition, a problem-oriented book of how to do just about everything.
By Damian Conway, the best explantion of how to do standard Perl 5 object-oriented programming.
Damian's follow-up to Object Oriented Perl shows how to write good, maintainable Perl code.
Published here in Chicago, it's the only magazine devoted to Perl.