In preparation for a business-related internship, I’m reviewing topics in micro- and marco-economics, and after that will review topics in business. I’d like to point out that my favourite book on MBA and business so far is, hands-down, the Personal MBA
Buy it, and read it twice. Take a look also at the list of books i recommend.
Similarly, the Harvard Business Review offers a lot of interesting articles on business, and is available here: https://hbr.org/topic/managing-yourself