#28540
HAT-Matrix.com is a new representation of an old standard--the Help Authoring Tool (HAT) Comparison Matrix that was available from helpstuff.com for five years (2001-2006). But instead of a static list, this site uses a searchable database. And instead of someone choosing the tools that are included, vendors choose whether to include their tools.
HAT-Matrix (2006). Resources>Documentation>Software>Help
#13673
A page about each of the major online Help technologies: HTML Help, JavaHelp, WebHelp, WebWorks Help, WinHelp, and WinHelp 2000.
#29918
A weblog for writers of documentation and users of Help Authoring Systems.
#25846
Classic information for Windows Help authors.
Carroll, John M. PC Users Group (1995). Resources>Documentation>Online>Help
#20702
Examining documentation and help systems for software and consumer products.
Meyer, Gordon R. Usable Help. Resources>Documentation>Usability>Help
#20886
User Assistance Resource Directory: Web Resources 
The following general resources are Web sites of interest to Help authors, technical communicators, and programmers.
#32975
A collection of screen captures from online documentation, to permit technical writers and documentation designers to review a variety of visual styles.
Gallery of Onscreen Help. Resources>Documentation>Help>Online
