In short, the task of the KDE quality team is to detect the loose ends in an application, and try to tie them together. The team objectives are similar of those of a project manager in a commercial organization. The main challenge of the team member is to interact with different areas of the application development, as there is much to learn.
But that does not mean you have to know all these areas: you can focus in one specific point of the application, like answering users questions, writing articles, documentation, creating artwork, whatever you want! Just find a lacking area and start working! After you feel you have the time and will to try something new, come back here to check the information available for that specific task. This guide's job is to organize all practical information to help you.
There is also a version of this guide at the KDE Wiki Site (wiki.kdenews.org), but it is not updated anymore. If you discover errors or if you know how to make this guide better, feel free to modify the KDE repository (if you have a SVN account), or e-mail the quality.kde.org Webmaster with your changes.