Klaus, I have an idea.
What about to install mediawiki and put the documentation on it.
And then allow some users (that you can trust them) to edit the wiki?
I know, you have not so many time to create help documentation and I understand it as programmer.
Because we all have fun to programm but not to write the boring help.
But If you let us to create help in this way, I think, it can give us good result.
If you want I can help you to start, install and write basic docs, because some time ago I have been playing arund the mediawiki and found it very good for documentation.
What do you and others think?
Regards
Greg