As for Xamarin University, the vast majority of that experience is live, interactive learning with a teacher. That's why it costs money. The recorded versions of those interactive classes aren't that useful on their own. But, we're working on developing some good standalone e-learning content and when we do it will be widely available.
This includes hundreds of samples: http://developer.xamarin.com/samples-all/
And lots of detailed guides: http://developer.xamarin.com/guides/
And dozens of videos too: http://developer.xamarin.com/videos/
As for Xamarin University, the vast majority of that experience is live, interactive learning with a teacher. That's why it costs money. The recorded versions of those interactive classes aren't that useful on their own. But, we're working on developing some good standalone e-learning content and when we do it will be widely available.