Well I sent a message to Chainfire and no I haven't done guides but I have helped a fair bit more than most members I see.
I haven't done any guides because any of the things I could do one about already have stickies/threads
Sent from my ice cream powered Nexus S
Sometimes it is possible to find abandoned threads and then do a new thread to replace it, but that takes time to get the links to that thread replaced with your own so people stop going to that old thread.
Another possibility is to find a guide or thread where the original poster has moved on to a new phone, and then contact the forum admin to request that the thread ownership be transferred. If the OP is willing then that is an easy process. You don't get to keep their thanks from that thread however. :-/
Another possibility is to do the guide in a different format. If there is a text guide on how to install a firmware+ROM, then do a video guide, or do a better text guide with screenshots.