If your backend exposes a textbook REST interface, integrating it with AngularJS is almost no work at all. $resource is all you need. In case you have one or two non-RESTful endpoints here and there – and honestly, who doesn't? – $http is your friend.
In an app I'm working on, I have a front-end built with Angular talking to a Tastypie back-end. Since Tastypie implements all the boring REST CRUD for you automagically, integrating the two took about fifteen minutes total.
If there are there any specific questions/issues on your mind, ask away.