I was assigned several in lae school, they wouldn't be relevant to you. Any introduction book on corporate structure and corporate governance would do as a foundation (for your jurisdiction) I would imagine, any specific questions you would have after that would be answered in the followup material in the references of such a book.

Business school and law school students have to buy many books on these topics, and their resale value is low. Any second hand book shop has lots of them, so does abebooks. It doesn't have to be expensive, it's the time you have to invest that 'costs' (in the generalized economic sense) the most.