I've read this question: SproutCore javascript, but as it's four years old, it is outdated. both the frameworks and the linked pages have changed. Apart from that, in four years one could write a lot tutorials. I googled around but couldn't find anything. I've seen the guides on sproutcore.com, but they are far from complete. I can hack together a simple one page interface, but with my current knowledge of the framework, using it would be something more like a handicap than a benefit.
At the moment, the guides and showcase are definitely the best sources of static information. We do realize that the guides are a bit outdated and incomplete and actually have a thread going right now about what needs to be added.
However, the mailing list and IRC are now both very active and picking up steam as we all try to help out and answer questions.
Additionally, we are in the process of getting Sproutcore added to TodoMVC which should give you a good starting point.
If you're interested, we would love to hear your thoughts on what material we can add to the guides to improve! Just visit the guides' GitHub issues page and add an issue for what you'd like to see!
Edit: Also, we are making a push to add some questions to SO so that users can easily find proper examples of how to solve common problems, so definitely check back regularly and view the recent ones.