https://wiki.ubuntu.com/QATeam
The Ubuntu quality team is an open team of people interested in helping make ubuntu be the best it can be. This involveds writing and executing testcases and helping developers and other community members perform QA tasks.

You can meet the team in #ubuntu-quality on the Freenode network.
Please, subscribe to our mailing list at https://lists.ubuntu.com/mailman/listinfo/ubuntu-quality