This was all two years ago but...

Articles, forums and some books.

I did some machine learning competitions on Kaggle. It was great for motivation, lots of practise and a helpful community. Takes a lot of time though...

I checked on none because I din't find "All" option.

Single source is only truth when it comes to a mother womb who delivers a child. But learning process needed to be like a horse which delivers at footstep though it may be painful dirt or sweaty fruits. We have the choice which one to inhale like a duck.

Thus, my suggestion is that inhale everything as far as possible you can and just do a little fart if you din't like.

All of the above, apart from paid lol.