Creating a Help File

I want to create a help File for my app.
I want to know if there is an easy way to create this with a 'free' program or something like this.
I tried the Help Workshop wich is shipped with visual Studio, but I don't really know how to use it.

Here is a cheap and easy to use help file creation program called Samaritain

http://www.netronix.ca/en/index.shtml

thanks,
But do you know something wich is a freeware??