Joe Welinske put together a company called WritersUA, (formerly WinWriters). I have attended their sessions in the past and found them to be entertaining and comprehensive.
"WritersUA specializes in providing quality training and publications for the community of user assistance professionals. The world of user assistance comprises a variety of techniques and technologies to make working with software a better experience. This includes online Help, wizards, web sites, printed documentation, and improvements to the application user interface."