Manual pages for these commands: XF86Config, X, XFree86, Xserver, Xsecurity, xinit, startx, xdm, fvwm
XFree86-HOWTO: http://sunsite.unc.edu/LDP/HOTWO/XFree86-HOWTO.html
XFree86-Video-Timings-HOWTO: http://sunsite.unc.edu/LDP/HOTWO/XFree86-Video-Timings-HOWTO.html
Official documentation from The Open Group:
ftp.x.org/pub/R6.4/xc/doc/hardcopy/
All listings referred to in this article are available by anonymous download in the file ftp://ftp.ssc.com/pub/lj/listings/issue56/3083.tgz.