This is the second book about Backbone and, honestly, the more I read, the less I understand about it; but I believe that's absolutely only my fault.
Although the book explains each of the Backbone classes in deep, it never really connects one to another. It seriously lack a whole description on how to build an app from start to finish. Even if you know everything about collections and models (and that they represent a table and a record, respectively), how to create a View and how to route things around, you seriously lack the idea behind connecting one to another -- although Views are shown using Models directly, it should actually go on how to draw several models from a collection in a single step, for example.
So, although good for understanding Backbone classes, it lacks on the general building of a Backbone app.