Some places to start.
In the Device section of your XF86Config[-4] file it looks like you have a "Chipset" (or Option "chipset") line. You can probably comment out that line since the chipset will be auto-probed when X starts. Other than that make sure your Driver line is correct.
Since you are new to Linux, I would recommend reading the following mannual pages for more background information:
The X man page can point you to lots of other documentation. It's more of an overview of the X-window system. Also, you should be able to get documentation in German if that is your prefered language, just check your package manager (dselect by default).
FYI some usefull document tools aside from man are apropos, which searches the mannual database for a string you provide and info, which some programers (particularly GNU) seem to prefer as a documentation method (though they generaly provide man pages as well)