I won't waste your time on a synopsis since I think you know the story, even if you also haven't read it. But I really encourage you to make the time to do so. It's an important read. What struck me the most was how unbelievably boring the first part of it was. In the beginning, Anne was still writing about her normal life--her friends, boys, and school. It was actually pretty hard to get through and I imagine it would be even harder for a male. Noticing the change in tone and what was important to her as time progressed was most interesting.
I mentioned in a post a couple of weeks back about how my knowledge of the impact of World War II on Europe has really developed during my time living here. It's reading books like this one and War Brides (see review here) that have really facilitated this. I encourage you to read this book and make sure your children do as well. Most people will not have the opportunity I have had, but if you get the chance to at least visit Amsterdam and the Anne Frank house, I really recommend it. It's a very moving experience.