- NN and DL: probably the most recommended online book
- victorzhou blog: not read but recommended
- How NNs are trained: meh but 'further reading' links are great
- step by step backprop: very detailed and easy to grab
- PDE by 3b1b: math | YT
- 3b1b on NNs: playlist | YT
- NN in 13 lines of py: a good start point imo
- NN cs231: academic | mathy | high level
- recipe for training NN: advanced tips | for later
- guide to tensorflow: intro guide | for later