Andrus,
Try Help and Manual. It can produce browser based help, WinHelp, HTML Help, publish to PDF and print a manual, all from the same file. It is shareware so you can try it before you buy it. It is available at
www.helpandmanual.com.
I looked at several products and chose it because I found it more intuitive than the others that have been suggested to you. If you are a technical writer who will be working on the help file full time, RoboHelp may offer you more, but if you are a developer that needs to produce documentation from time to time, take a good look at Help and Manual.
David