It's an understatement to say that I'm a fan of Code School. I love the way they've blended professional video screen casts, live coding in the browser, and gamification to make learning fun again. The music is a little campy sometimes but overall I'm addicted to it as you can see from my report card.
Yesterday they released a new course sponsored by Google to really dig into Chrome's DevTools. I've always tinkered with DevTools but have never become a power user. I was always looking for some sort of tutorial to explain everything to me. Well here it is! The course involves beginning and advanced DOM and style manipulation, working with the console, debugging JavaScript, memory profiling and improving performance. The best part is that the course is free to everyone! No need to purchase a subscription... but I would if I were you.