Reading Usable Help
@UsableHelp on Twitter
Gordon R. Meyer
Help creating Apple Help
If you're creating help systems for Mac OS, you're probably painfully aware that the official documentation from Apple is out of date. The existing documentation is correct, almost entirely, but the new help system features that were introduced with Tiger are not covered.
So, then, you'll definitely want to visit Andy Matuschak's website where he has graciously, and helpfully, written about his Apple Help development experience. It's useful even if you're not interested in new features; it covers the general process of creating Apple Help too. (And thus, even if you're just curious, it's a good piece.)
Finally, and perhaps even more importantly, Andy provides wireframe templates derived from Apple's own layout for Tiger help. If you want your product to match what Apple provides, and you want to save a lot of time in coding your own HTML, then these templates are a must-have.