Not only is a good wiki a fantastic tool for this, I've got one for you that's zero-installation and zero-cost. Zwiki is a robust and proven wiki engine and I'm still offering http://zwiki.org/FreeHosting. Later, export or zsync the content to your own Zope server if you wish. I use it all the time to organize information and and document procedures for my clients. The lightweight page hierarchy, email integration and integrated issue tracker come in handy. If you'd like further tips on this, ask me in #zwiki on irc.freenode.net.