I have a website where I have a handbook online, in WordPress Pages. Chapters are organized as parent Pages, then each parent might have 6 or 8 child Pages. I can list all the Pages using wp_list_pages and have it formatted as a sort of table of contents. This part works fine.
I would like to be able to have the visitor browse the pages sequentially, rather than having to click the back button or use the menu navigation after viewing a Page. So, when they start reading at Chapter 1, and they want to go to child Page 1a, at the bottom of Page Chapter 1, there would be a link "Next" and possibly list the page title, then the link points to Page 1a.
Let's say you're in the middle of the Pages (Chapter 5 for example): there would be a link to the previous Page (Chapter 4d maybe) and the next Page (Chapter 5a.) The next and previous pages to show as links would come from wp_lists_pages and use the menu order (rather than previous/next by date.)