Books are rich text posts that any registered user can edit (blogs and forum posting can be edited by the author and admin only)
 
Book pages can be organized in hierarchy (i.e. chapter, section, sub, etc) and navigation links are automatically generated below the page and in the breadcrum. In addition, when viewing a book, the table of content is shown in the left side-bar  to further ease navigation.
 
For each page, the list of sub-pages is shown just below it. So no need to hand enter table of contents. Those automatically generated section contents can be sorted using a system of weights... which works but can be tedius. I strongly recommend to simply number the pages (1. Page 1, 2. Page 2.) as mechanism for sorting these into a logical order. Referencing page can then be "goto page 2.1.4 of the user manual"