In seventh grade, I was introduced to book reports. I was to read books from a school prepared list and submit a type written paper. I got a list of guide questions on what I'm suppose to write about. They are basic questions about the plot and the characters of the book and what I think about them. This was before those Idiot Guide Books became popular. In the first few attempts of submissions, I tend to tell the story myself, then it evolved to telling the story as I enjoyed them. I was in eight grade, yes, the second year of attempting to write something passable for a good book report, when my teacher read my book report on a novel by Robert Heinlein titled Methuselah's Children in class. She remarked that this is how you write a good book report. Afterwards, I read my copy of that book report, and read it again, trying to find out what I did right with it. I asked my teacher about it too. I never answered a single question in the list of guide questions. Right, and you had lots of fun writing it too. Aha. It shows. Well my teacher's smiles tell me she had lots of fun reading it, that is all.
When I read a book, read it to understand. Walk with the pace of the story. You will soon get to that part of the novel when everything seems to slow down and like Flash seems to move from one part of story to the next. You're in the groove. Then it hits you with a blind corner. I see fear, wonder, anger or gratitude there. Here is the point when I know what to write in my book report.
Unless you get to feeling these emotions, you won't know what to say. If you don't know what to say, you're bound to copy what other people think about the book and use their words not your words. So feel it. then tell me about it the best way you can.