Wikihow; The online how-to guide
I came across this one recently; wikihow is a wiki, just like wikipedia, where any user of the site can make changes. This one is fairly specific, in that it focus’ on guides on how to do stuff.
As of this posting, they have over 23,000 articles, so there is bound to be something of interest for most of us. Of course, if not, why not write your own guide?