If you feel comfortable with React, Redux, and Immutable.js you can skip this.
Shasta itself is simple, but it's built on the shoulders of other great projects. Before diving in, we recommend reading the following:
- Why React?
- Thinking in React
- Displaying Data
- Multiple Components
- Reusable Components
- Component Lifecycle
PS: Don't pay too much attention to the code examples, Shasta simplifies things so the code is quite different.