http://puppetlabs.com/blog/the-next-generation-of-puppet-module-testing
http://puppetlabs.com/presentations/puppet-loves-rspec-why-you-should-too
http://puppetlabs.com/blog/verifying-puppet-checking-syntax-and-writing-automated-tests
http://puppetlabs.com/presentations/beaker-automated-cloud-based-acceptance-testing-alice-nodelman-puppet-labs
http://rspec-puppet.com/tutorial/
Beaker:
http://puppetlabs.com/search/node/beaker
http://puppetlabs.com/presentations/beaker-automated-cloud-based-acceptance-testing-alice-nodelman-puppet-labs
http://puppetlabs.com/podcasts/podcast-beaker-cloud-enabled-acceptance-testing-tool