Harry, a History is a history of the Harry Potter phenomenon written by Melissa Anelli, the editor of the HP news site The Leaky Cauldron. It's also an account of her activities at the Leaky Cauldron, from the early days when she was just out of college and entering what she calls the "fandom" to the later, frenzied days surrounding the release of the last couple of books, when she was podcasting live in front of hundreds of people at bookstores across the country and going to Edinburgh to interview J.K. Rowling. She even got to tour the movie set during filming (going into raptures at the sight of the Great Hall and, of course, noticing the little things the film set got wrong).
One part of the "fandom" that I found interesting were the "shipping wars": online debates between fans over whether Hermione should/would end up in a relationship with Harry, or with Ron. I had forgotten how crazy things got towards the end of the series' publication: the undercover sting operation that led to gun shots, the New York Times book review that came out before the book's release (anathema to any fan trying to avoid spoilers!) and the thousands of people at J.K. Rowling's publicity events. If you find the beginning of the book slow, with its chapters on wizard rock, fan fiction, and the books' fundamentalist challengers, you will not miss too much if you skip those.