I recently struggled a little to find good documentation on AngularFire 2.x.x – basically the version post when Google bought out FireBase. If you search for Firebase and AngularJS, or even if you go to http://angularfire.com, it all goes to the older version.
However, there is some fairly good documentation on the GitHub repo (https://github.com/firebase/angularfire) – but best of all, one of the examples on the repo has been migrated to the latest version:
I found this example to be fantastic, not only of AngularFire but also AngularJS in general. If you are looking for easy to understand examples of great architecture, I think you could do a lot worse.
The architecture is modelled after this excellent style guide: