What is the best way to learn backbone.js?

Hello forrst, I have a problem. I am going to learn backbone.js! Now my question is, how to learn it the best way. I looked at the Documentation of backbone.js first! But I did not even get it with the Model-Router-View-Collection Structure, but I do use CodeIgniter for coding in PHP (MVC-Structure). Then I looked at the example, but just got a "Backbone.View.extend"-class for rendering a static text like "Hello World {id}" in a list. But how do I implement Router's, Model's and Collection's ?

Please help!