Michael Kimsal has put together a small page to help you get started using the phpUnderControl continuous integration system:

If you're not using phpUnderControl, you owe it to yourself to check it out, as I think 'continuous integration' will likely change the way you think of development. I've used CruiseControl in the past for PHP, but the PHP-specifics phpUnderControl brings to the project are too much to pass up.

The page mentions some of the common issues you might have in getting started - installation problem, the use of the PHP Code Sniffer and the Project Mess Detector from PHPUnit.