I recently needed to write a simple help file for an application I had developed and spent some time looking for an affordable help authoring solution. After trying a few demos of commercial software I stumbled across this superb piece of freeware called HelpMaker from Vizacc.http://www.vizacc.com/
As well as the text editing application it comes with a range of other tools such as a button maker, pdf creator and so on.
It is so good, I cannot believe it is free and thought I must share this with you all. Appologies if this is old news and everyone already knows about it.