Free book: Invent in real time your Own Computer Games with Python.

Very accessible (as 10 to 12 years old) this book teaches you how to program in the Python programming language. Inside each chapter is organized to give you the complete source code for a new game.

As a second edition, it has revised and expanded content,

including a Pygame tutorial to make games with graphics, animation, and sound.

The book and the programs are open source (free to copy and distribute). If interested a print copy can be bought on Amazon.com for $25.