There are 14 books in the Wizard of OZ series (This is excluding Wicked and other books created by authors other than Frank Baum. I still like other media of it), each with different stories, different characters, and just colorful adventures for days! (I am on Dorothy and the Wizard in Oz! I havent read all the books yet, but I will get there soon!)
The books are a bit dark and sometimes confusing, but the story is very intresting and there is a lot to the world of Oz. Especially when it comes t the characters. Dorothy isn't the only main character of the series, and the Wicked Witch isn't truly the main bady of Oz.
I am really surprised that there hasn't been a successful TV show made from these books, let alone a movie trilogy (or to some extend, an MCU of the OZ) Like there are so many unique characters in the Oz world that a movie can be made from them.