Truth be told, out of respect to their IP, I should not post their content here. But I can say that they helped me understand some of the basic building blocks of building a Skill. You can probably search around online and get the same material for free, and I have a feeling they will post the lessons online at some point.
The biggest surprise for me was that you should build the Lambda function and the Alexa Skill at the same time, also you don't need to publish either in order to start testing. Here are two screenshots and screencast of the hello world app I build. You can see that neither was in a 'published' state but they were happily interacting with each other and my EchoSim.
Stay tune for my further progress on playing with this new interface. I am having so much fun that I even ordered a Echo Tap. :)