In book 2, Harry discovers a secret room in the castle, and is attacked by a lizard. There is also a talking book. It reminded me of Stevie Wonder's seminal 1972 album, Talking Book. He saves a little girl.
Book 3 is a family story, with Harry learning lots about his parents and his Godfather. He also does a lot of sneaking around and gets a magical map. The book is also about racism. Get used to that, too.
In Book 4, Harry is entered in the junior wizard olympics, fighting dragons and swimming underwater and going through a hedge maze. At the end it turns out that the bad guy (I said his name at the top) is back, which eats shit. Also, Harry has his first crush on a girl, and starts growing hair in places.
Book 5 is about a super secret club called the Order of the Phoenix, dedicated to fighting the bad guy wherever he goes. It is also about exams. Exams in England don't make much sense, and wizard exams don't actually seem any stranger than secular exams. I will spoil it for you now: Harry ends up doing pretty well, but not as well as his know-it-all friend Hermione.
In Book 6, Harry gets some help with his schoolwork from an old book. It's kinda cheating, but he thinks maybe the book belonged to his dad (it didn't), and I thought maybe it had belonged to his mom (it didn't), and it isn't until the very end that it turns out that it belonged to bad guy #2. Also, Harry's wizard mentor is killed, and leaves Harry with a daunting task that leads directly to book 7…
In which Harry goes looking for about 10 different magical items that he needs to either possess or destroy in order to win the fight against the main bad dude. His friends fight and they spend a lot of time camping, and then there is a big battle at the end and a lot of complicated stuff about magic wands. You could replace most of the second-to-last chapter with a discussion about the merits of turbochargers as opposed to the merits of superchargers if you want, Harry is going to recap all of the wand stuff in a dramatic monologue at the end anyway. Oh, and it turns out bad guy #2, well, I don't want to spoil it.
I got to Harry Potter by a circuitous route, after reading Can You Forgive Her, Phineas Finn, everything by Haruki Murakami, The House of Mirth, and The Satanic Verses. One day I had an extra 5 minutes, and I started reading a wikipedia article about magic wands in Harry Potter. I was warned that the books weren't really about magic wands, but still I embarked on the journey.
Although I wrote the review as if you hadn't read it, I don't feel the need to offer a recommendation. Either you will read it or you won't. You know which you are.