There are some resources around; but the best place to start learning how to use SDK is to read the sources (runtime.js) directly; You'll learn how to read source code, you'll learn how are things done in SDK, and you'll learn a lot of javascript along the way.
You could start with how the line-sight behavior is implemented, and than continue from there!
Also, check out the SDK template, you'll se that some of the basic stuff is implemented so you can get a good start...