Thought I'm certain the answers are laid out on the forum already, my initial search has not returned them. I need to understand how to add a table of contents to a book that will update automatically.
The only special consideration for my purpose may be, that midway through the book 16 pages of photos will be added which should not affect the page count (they will be unnumbered).
InDesign's standard built-in TOC feature works on paragraph styles and does not update dynamically - you have to regenerate when things change. To get a fully dynamic update you can use cross-references, but be warned that cross-refs that cross beteen documents cand be very fragile and flakey.