Harry Potter and the Half Blood prince
This is one of my most favorite books EVER! It is a really good book with a LOT of detail. It starts off with Dumbledore coming to Harry's aunt and uncle's house to pick up Harry. They then go to get one of Dumbledore's old friends out of retirement to come work as a professor at Hogwarts school of Witchcraft and Wizardry. After that they travel to the Burrow where Harry stays for the remainder of the summer. Before he leaves Dumbledore tells Harry that he had set up private lessons for him during the course of the upcoming school year. Harry has fun for the remaining days of summer with his friends. Then school starts and they have a new teacher and some of the teachers switched classes. Then Harry goes on an adventure with Dumbledore that all the lessons have been leading to which results in a death that Harry knows he will never forget.