This just sounds to me like the manual is essentially being converted to html, right?  If you want to get fancy, make menu items for major chapters and just make lots of links and invent easy in-line methods of navigating to the 'next' 'prev' etc. pages.

The first thing that comes to mind is to simply paste into text modules, and reformat and insert images, etc.  Use specialized modules when it would be called for like links or sub-document lists but generally this will consist of editable text modules.  The built-in CMS structure of DNN will make it easy to maintain and update the manual(s).

I'll have to take a look at the article and publishing modules, but it seems to me that a sensible bet to get the most out of DNN would be to make the manual into a web site.

I just installed the Help module on a test server.   Do you know if the future release will have any type of approval process?

I need a module almost identical to Help, with the categories, and child categories but also include a workflow/approval process so that there can be others assigned to publishing when this beast is completed.