I can also heartily recommend Perl Testing: A Developer's Notebook as a practical hands-on guide to TDD with Perl. It skimps somewhat on the "general methodology" stuff but that's just the type of book it is, light on theory, heavy on practice.

For a slightly more fundamental and verbose approach you could try Test Driven Development By Example by Kent Beck. The code in that book is all Java, but it's easy enough to extrapolate to Perl from that.

And testdriven.com is a good resource of news in this area (if also rather Java-heavy).

Also, check out chromatics "Refactoring Everything" series of articles. While not nominally about TDD it contains grains,gems and boulders of wisdom on the subject.