This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
The JavaHelp API uses url base hyperlinks, I believe. The only difference is that they point to the local file system instead of the internet. Your best bet would be to construct a url using getClass().getResource("your_file.html").