Ich denke viele 3rd-party-Programme sind in deutsch verfügbar. Schau einfach, was du täglich benutzt (Kalender, Wetter, IM), und installier die Programme auf deutsch
In case your German isn't that good yet:
There are plenty 3rd party applications that ship with a German translation. Simply check what programs you use daily/often (PIM apps, weather, IM apps), and install them in German.
Oh, and in case you didn't know LEO yet...
http://dict.leo.org/ende
Should definetely be in your bookmarks (both on your PC and your Q
)