Modern Perl: the book explains how Perl 5 works and how to take advantage of Perl. The fourth edition was published by the Pragmatic Bookshelf. You can download Modern Perl 4e free from the Prag site.
I no longer participate here in any meaningful sense.
I've written, edited, and contributed to other technical books.
In my spare time, I contribute to Trendshare's novice stock market investment guide and help family members with a healthy blender recipe guide (they spend way too much time answering how to make a smoothie).