jumping for reactjs newbie to pro. Resources?

Hey all! So last weekend I made my first ReactJS application after about a year of being a Rails dev for a "take home" project for a startup in town. To my delight, they loved the application and offered me a job shortly after the interview was over.

Everything I know I picked up from the Reactjs website, and their tic-tac-toe tutorial. Is there a good place to pick up a mid/high-level understanding of Reactjs?

Thanks!