I was a TA for Neuromatch Academy, a 3-week online Summer school in computational neuroscience.
My first understanding towards fMRI data came from the fMRI Bootcamp by Rebecca Saxe from MIT.
I was introduced to the Neural network course (CS231n) by Fei-Fei Li, Andrej Karpathy, and Justin Johnson from Stanford in a neural networks course, and I love the way they communicate the concepts.
Neural Network and Deep Learning by Michael Nielsen also introduces neural networks in a very approachable way.
Special thanks to Eric, who has been teaching me a lot of math in our spare time.