Best Online React Video Tutorials (2019)
From FreeCodeCamp an hour-long introduction to React and its major concepts.
Scott Tolinski of LevelUp Tutorials has a friendly way of explaining even the trickiest React concepts. There are additional courses on Redux, React Testing, and Intermediate React that are also worth exploring.
Frontend Masters has solid content and this course by Brian Holt is a detailed look at React via building a Petfinder web app. He also has an Intermediate React course that covers testing and more advanced React concepts.
The screencasts version of the excellent book.