If you are just getting started, we recommend you begin with the Hello, Cinder guide. If you'd like to just get a sense of what's in Cinder, take a look at the Namespace list. And don't forget, the samples are still the best way to learn Cinder for now as we work to fill out the documentation.
Hello, Cinder
Using Resources in Cinder
Cinder + Boost
The Anatomy of a Cinder App