The Design of Software

Can anybody recommend a good program for creating help files that compile as CHM and can be output for the web? I have the microsoft SDK for creating help files but I want something that has a gui interface for creating the files.

Depends how much you want to spend. We are currently using doc-o-matic seem to do everything we need, and loads more, but it is quite expensive.

We use Help & Manual ( http://www.ec-software.com ) and would highly recommend it. As well as producing the usual formats (hlp, chm), the same source can also produce PDF manuals as well as plain HTML for use on your web site.

+1 for Help & Manual

Because you learn it quickly and can output to many formats.

I have also used CityDesk for this. It produces CHM and html files easily.

Another +1 for Help & Manual.  I've been really happy with it.

http://www.helpmaster.com/ provides a thoroughly complete overview over WinHelp/HTML Help editors. You might also want to re-read a previous discussion of the same topic on JoS,
http://discuss.joelonsoftware.com/default.asp?joel.3.17274.4

I ended up with HelpNDoc due to its intuitive user interface
(plus it is free), but this just creates CHM files.
http://www.ibe-software.com/products/software/helpndoc/

Roland,

According to their website, HelpNDoc is only free if it is for personal use and 'you can't use HelpNDoc or its generated files for profit.' - otherwise a license is 45 Euros. According to the site, it also puts some text at the bottom of each help page.

It does look like a good product, however.  I'm looking to write a few help files for internal company apps and will probably download the free/demo version to check it out.

HelpMaker from http://www.vizacc.com/.  FREE!  Works great!

You may also look at another help authoring software, Dr.Explain, which is built on the brand new technology.

Dr.Explain captures windows from a live application, creates screenshots and automatically adds references to all window’s controls: buttons, edit fields, radio buttons, dropdown lists, and other elements. You must just add some description if needed. This considerably reduces the time of documenting the application’s graphical user interface.     

I invite you to look at the project at http://drexplain.com 
I hope you will find the concept interesting.

This depends on what type of help file you are generating...

If it's an automatically generated code document that you want (i.e. APIs etc) then I would recommend:
NDoc for C# and VB.NET
or
DOxygen for C, C++ (and several others with a filter)

If it is for you to generate a document for a program then look at:
HelpMaker - it's free for commercial use and generates several formats. It has a few minor funniocities but once you are used to it, it is nice enough to use.