One of the areas I have been focusing on recently is the docs for IPP developers as I work on creating some simple sample applications.
A critical element of the documentation and learning material is the IPP programmer's guide. It provides a technical overview of building apps and is also a thorough reference for the APIs at the same time. For example, it talks about the established MVC design pattern and explains it with some animated flow. At a more detailed level it talks about QuickBaseDTOArrayCollection, how it enables refreshing database records in the view or the object instance automagically and so on. It also talks about the Kingussie framework which is based on Adobe's Cairngorm MVC-based framework although a comprehensive understanding of this is not necessary to get started.
The documentation is pretty rich and comprehensive. However, it might seem like the programmer's guide attempts to be a tutorial and a reference guide at the same time. There are some known issues that are being addressed (as I blog) as well.
At a time when Facebook is attempting to democratize its governing and opening it to users, it's appropriate to provide a Call For Action to the IPP developer community to get involved in improving the docs. Future versions of the documentation will make it much easier to submit and view comments "inline" but in the meantime, all feedback (good, bad or ugly) and ideas are always welcome.