I have started to write the game. I work with a TiddlyWiki, and I think that it is a great way to start writing while still exploring the subject.
I have published the wiki via my Dropbox, Behind the veils of night - an old school D100 game. You can read the rules and campaign background there. As the wiki can't save to my Dropbox account you can't make edits to the wiki. You may however download it.
The name of the game/campaign is tentative at this point.