did you really mean tutorials? Doc's do not look to bad to me.
http://docs.sproutcore.com/#doc=_global_&src=false
But understanding a framework is not just about looking at the doc's - because using framework means understanding it beyond the simple use of a control or procedure. BTW it maybe open source but Apple used it for mobile-me and to my knowledge is still using it.

The point of sproutcore is it provides a framework for creating CRUD client side apps in javascript. It makes it cross platform and has touch etc making it available for the mobile market (ipad too). It also allows plug-ins etc. Of course there are several others out on the web and that do similar jobs (cappuccino for one).

Johnf