The KDE Translation team works beside the Documentation team.
There are many ways to get in touch with the team:
You can chat with the team in #kde-i18n on irc.freenode.net, or learn more about IRC.
The team discusses activities on the kde-i18n-doc mailing list, learn about mailing lists.
KDE uses custom tools to internationalize the GUI and documentation of programs. You will want to review The Translation Howto to learn the process. To dive in and start translating, head to KDE Localization Home Page and choose your language. From there, you can contact the specific team for your language and download the translation files.
There is also a scoreboard showing progress of urgent teams.
Getting started in a big project can be hard. Here are some people that can answer your questions and help you get started.