Perl Testing: A Developer's Notebook
by Ian Langworth and chromatic
2005 O'Reilly Media, Inc.
I just got this kickass (note)book last week and even though I'm in a very tight schedule right now, I still find time now and then to check it out. I'm already at chapter 3.
The notebook is separated into 9 chapters, covering all the major things you would think of (and some you don't): Beginning Testing, Writing tests, Managing Tests, Distributing Your Tests (and Code), Testing Untestable Code, Testing Databases, Testing Websites, Unit Testing with Test::Class and Testing Everything Else.
It has a lot of code into it. It's basically a programming aid rather than free reading. It explains tests out of working on and writing them instead of the mere theoretical aspect. It's like the science teacher who showed you the formula while making something burst into flames. Quite fun and you always feel like you're getting much more than just background. The page magins are also laced with comments and short tips along the way the relate to whatever paragraph you're reading.
Even thought it came out in '05, I still haven't had a change to check it yet. It's still a very recommended reading to any programmer!