When I was learning Flux I thought this video series[1] was really helpful. That being said, I've switched to Redux now and am much happier for it. If you're into videos I highly recommend Dan's (creator of Redux and on React core team) Egghead series[2].
[1] - https://www.youtube.com/watch?v=Pd6Ub7Ju2RM
[2] - https://egghead.io/courses/getting-started-with-redux