Hand-written HTML in dreamweaver (although 70% is written by hand in homesite (so no wysiwyg)), then compiled using FAR HTML into .chm and online help
I'd recommend dreamweaver over any help authoring toolkit. We looked at many of them and all their HTML editors in general suck bigtime compared to dreamweaver. Using the elcheapo toolkit FAR HTML, it's very easy to setup TOC's and other stuff and it can generate an on-line help version as well