Mouse Systems has a web site at
http://www.mousesystems.com/. They have a Windows driver if you need one.
The Linux Serial HOWTO is available from mirrors of sunsite around
the world. If you don't know where your nearest mirror is, start at
http://sunsite.unc.edu/mdw/linux.html
Fuller details of the Xconfig and XF86Config files are found on the
relevant man pages, and in the documentation about installing X windows
such as the Xfree86 HOWTO. Also, see the XFree86 FAQ at a mirror of
http://www.XFree86.org/.