Blogs
KDnuggets
KDnuggets is a great tech website with lots of quality blog posts. On top of content posts, they also have opinion pieces or career advice posts.
Colah.io
Christopher Olah is a machine learning researcher who loves to write blogs to explain complex machine learning concepts. He has great blogs regarding deep learning.
Machine Learning Mastery
Machine Learning Mastery is a platform where many people write interesting blogs about machine learning.
O'reilly
Karpathy.io
Andrej Karpathy is the director of AI at Tesla. When he was a PhD student, he wrote a “Hacker’s guide to Neural Networks”, which is remarkably complete.