Getting Started
The easiest way to get started is to clone https://github.com/ysulyma/rp-tutorial, which is the video on the homepage. You can use that as a sample project structure and modify it to your needs. The source code demonstrates how to use a lot of the different features.
The deep dive goes fairly comprehensively through the entire process of creating, recording, and mastering a ractive. It also explains how to use several of the plugins/utilities.
Deep Dive Part 1: Authoring, Recording, Mastering
Deep Dive Part 2: Plugins+Interactivity
There is also a second tutorial focused on mathematical content (equations, 2d and 3d graphs): https://github.com/ysulyma/rp-tutorial-math, which you can watch here