Topic: Steps to build web app


I've completed the much lauded Ruby on Rails Tutorial by Hartl and am beginning work on my own rails based web site.  However I'm new to web development in general and come from a mobile development background.  My main question is does that book reflect how one actually would develop a website? (building small minute pieces that may never be displayed later) I figured the book is organized in such a way to portray the easy stuff first.
so what are the conventional steps taken in terms of development from model to view to controller and then also integration tests in a tdd development cycle?

Thanks a lot