Thanks for setting up this thread, Lee.
To start, let me detail the current state of each of the "Official" books that are sold by TGC.
All the books are designed to help you through the AppGameKit learning process with not only full descriptions of commands but also example code, complete (short) games and activities (with solutions) to help you master AGK.
The Official AppGameKit Beginner's Guide. This is just the first several chapters of the next book (see below). It should be more than enough to get you started with the AppGameKit even if you have never programmed before. This book was last updated to comply with the August 2018 release of AGK. If you bought an earlier version of the book, you can receive a free up to the latest version through Steam or TGC. You can also upgrade to the longer book through TGC.
The Official AppGameKit Tutorial Guide Vol #1. Again, this is a guide suitable for the absolute beginner and also cover AGK-specific topics such as Handling Multimedia Resources, User Input Techniques, Creating a Structure that can be Used for Most of Your Programs, Sprite Movement and Animation, Particles and Several Sample Games. Currently, the book covers up to the August 2018 release of AGK.
The Official AppGameKit Tuorial Guide Vol #2. This is a guide to what might be considered more advanced topics such as Tweening, Memblocks, 2D and 3D Physics, 3D Models and Games, Networking, and an Introduction to Game AI. Again, there are sebveral complete games and many activities. The book covers up to the December 2017 release of AGK.
The Official AppGameKit Tier2 Starters' Guide. This is a short book showing how to get started using C++ (Visual Studio and Android Studio) to create your Tier 2 games. It assumes you are already familar with C++.
Updates for each book are generally free.
That's the book plugging over!
If I can be of any help with anything within the books please put your question on this thread (or PM me).
It would also be useful if you could report any errors or omissions that you've spotted so that these can be corrected for the next book release.
And lastly, if there's any topic you'd like to see added to any of the books, please let me know.