At the Perl and Mac Development Blog, Christopher Humphries has written a tutorial on using Test::Class.

There are basically two schools of testing that is either Test::Harness based or Test::Class based. Test::Harness school runs a series of scripts which have tests in them top down, usually with a plan at the top of the file (plan is the number of tests you are planning on running). Test::Class manages itself, using Test::Class for tests and to run them...

Most of my test files use Test::More and little else, but Test::Class is a great way to organize tests for larger projects. Best of all, it works with all test modules built on Test::Builder, which is to say almost every test module on the CPAN.