I'm a Product Manager on App Engine and I truly apologize for the trouble you went through when you tried the platform. We have kicked off a large initiative to update and enhance our docs, and we just recently launched our new App Engine docs, an ongoing project of course. You can check them out here:

https://cloud.google.com/appengine/docs

Please give the new set of docs a try and please give us feedback when you see errors or generally when the content is not up to par with what you expect. There is a tool on the top right hand side of every page that explains this.

Thank you! Amir