v0.18 (I pulled from 47fd9d3, built on free bsd), clicking the "Help" tab in the 3D panel shows the Manual as an option in the left hand column.
The Manual is supposed to be a more linear, book-like way of learning about FreeCAD. Clicking on the Manual link replaces the current contents with the Introduction page of the manual; opening in an external browser gives the same page in the browser.
Unfortunately, parts of the manual aren't navigated like a written document.
In particular, from the Introduction page, there is no <next> or <prev> link. One has to guess that the next link on the left, "What is FreeCAD?" is the appropriate next page.
There are three links at the bottom of the "What is FreeCAD" page, and it is unclear whether they are meant to be read in order or if they are supplementary information one will "eventually get to anyway" if proceeding linearly through the document.
If one proceeds to the "About FreeCAD" page, it has a <previous> link that goes to the "Online Help Startup" page, not the "What is FreeCAD" page.
Questions:
1. Are the above pages (Introduction => What is FreeCAD => About FreeCAD) supposed to read sequentially?
2. Are the issues above just errors, or a result of the fact they are generated from the wiki (are they?)?
3. If they are meant to be read sequentially, shouldn't "Read More" be an optional section which, if present, is always followed by a <next> ... <prev> navigation line?
4. How does one configure the nav bar with an empty <previous>? Or should the first page go to ... the FreeCAD Start page?
5. How does one configure the nav bar to reference the Index in the middle? Is that link generated on the fly?
6. I would suggest that in book format, there should also be a nav bar at the top of the page, so one can easily skip a page without scrolling to the bottom.