I used to keep up a tips & tricks document, but that didn't really work out too well because it was difficult to update and keep my users current with the latest doc release.
Then I thought sharepoint would be perfect for this, but as some know too well, sharepoint isn't exactly the most user friendly solution.
So what I did recently was to leverage my employer's webhost account by creating a wordpress blog and registering a custom domain to point to it. Now I can update it whenever needed (from wherever), and utilize the feed reader built into Autocad to push updates to my users. I've found this to be hugely successful, and I've since opened it up to allow not only my own guys to contribute, but hopefully anyone who might be interested.
I've spent a fair amount of time adding some neato bells and whistles to make the blog both visually appealing, and easy to use. And best of all, it's accessible at the office, at home, and on the road. I'll soon even be adding a mobile version.
I would recommend this solution to anyone with the inclination to set one up. Of course, all are welcome to become a regular at my place.
See my sig to see what I mean.