The documentation is not impenetrable, it is just that AngularJS is a library that takes a while to get up to speed on. What is lacking right now is writing on best practices and application design. The O'Reilly book offers some of this, but generally it's just a warm-up with a couple case studies at the end.

http://docs.angularjs.org/guide/concepts is a model of good documentation, and http://docs.angularjs.org/guide/directive is exhaustive. The most difficult parts of the framework are very well-documented, but that some parts of the API have been woefully overlooked.

As you can see in that first link, Angular is an elaborate framework, and there is a lot to stuff in your head at once. This is why newcomers find the learning curve steep: It is a new way to write applications.