Well i think i can offer you some help on that question. Breaking Dawn is broken down into "books" but really its just giving you the story in a different way, from other points of view besides bella(like MidnightSun)..It goes in the right order like any other book, but your just going through parts of it from Jacobs point of view, but your still going through the book normally. Honestly, i liked reading the pregnancy part from Jacobs view, but i also wish that she would have put Edwards view of it in the book also(that would have been really cool). Some readers didnt like BD because of it being written like this, but i think it helped give us another point of view and also let us really get inside Jacobs head. It helped me understand him better.
The first book is in Bella's POV(chapters 1-7)
The second book is in Jacob's POV (Chapters 8-18)
The second book is also Bella's POV(Chapters19-39)
They do follow in order they are just in different POVs(which is cool especial if you like Jacob)