The book is not just basics. I've read most of the technical chapters and it is quite in depth. More so than any online resource. Plus there is the AI interviewer which is free and probably better than trying to prompt chatgpt yourself.
These days, I can't even be bothered. Sometimes I type 2 words may be 3 and o3 will do all the CoT style prompting on its own. I don't mind the wait.
o3 is wonderful in exploring codebases, especially on GitHub Chat.