Welcome to the forum.
Normally, I recommend Steve Grisetti's Muvipix Guide to Premiere Elements 11, but I am not sure if it has been translated from English to German.
However, Steve is the MOD (Moderator) in this forum, so should be able to tell you, if it has been translated. I just do not know.
One other possibility (though I have only seen the English version) is The Missing Manual Series. I know that they have Photoshop Elements 11, but could not find Premiere Elements past version 7, let alone in German.
Wish that I had more to offer, but good luck,
John T Smith wrote:
http://helpx.adobe.com/premiere-elements/archive.html is the only link I have... I have NO idea if a German version is included
Using that link and the Google Chrome translator, I got this: