Need a little advice regarding some watchmaker books..

If you are looking for a book that explains how things work, rather than how to repair or service, then The Theory of Horology is the book for that.

Again it's not a book that shows you how to service anything, but simply goes through the various areas of a watch and shows how things work and relate to each other. It's a textbook used in many watchmaking schools - I still have mine. Warning...there is math involved if you really wan to get into things in depth.