The Cormoran Strike Books In Order. These are written by J.K. Rowling, writing as Robert Galbraith. These are not children's books, and do not contain any wizards or indeed anything magical. Rather, they are a series of detective books (not aimed at children). I rather enjoyed them, but was quite surpsied later on to know that they were written by J.K. Rowling
Other Books by the same author, plus The Harry Potter series.