I’m sure you’ll be able to find plenty of information about shell scripting on the net. When I wrote this text (started 1999, with some updates until 2005) there wasn’t a good german introduction.
If you can read german: here’s the download.
Initially, I wrote this text for a school project. It quickly became too long to be a handout, so I published it on my page.
From my page, the text was included into SelfLinux. With SelfLinux being a part of the Knoppix distribution, my text has been pressed to thousands of CDs.
The Wikibooks project took the text from SelfLinux.
Both of those sites enhanced my text on their own, I see them as forks of my project.