I'm not a professional game developer. Not yet, but there is progress. ;) I have some experience with Unity 3D, but it isn't really what you would consider open source. And you are a bit limited concerning the free version. So, as I heard of the open source project libgdx I thought that I should give it a try.
On my search for a good documentation on libgdx I stumbled across this nice book. Even if there are many good tutorials and examples out there,
there is nothing really detailed which helps you to get through a complete game development project. This book starts with explaining how to install and configure eclipse to work with libgdx, goes over to some game dev basics and helps you to start a new game project which is extended more and more throughout the book. At the end you have a complete game, called Canyon Bunny, which should run fine on your android device. Further, there is a complete chapter about more advanced parts in game development like particle systems, physics with Box2D, and shader programming. Which are all well explained and added to the game example. If you get stuck at some point, there is also a great libgdx community which will help you out.
So even if you are a complete beginner in software development or have some experience with java this book
should help you to get trough.