My 7 year old son is reading at a 4th grade level. He'll be in second grade next year and he's asking for more books like Harry Potter. I've been told the first of those is ok for him (I've not read any of them as they've just not been something I'm interested in) but that moving forward In the series is not ok at this age. So, I want to keep him engaged in his reading this summer but also am concerned about finding books that are appropriate for a sensitive but bright seven year old boy. He also loves to read non-fiction like books about historical figures, sports, space, dinosaurs, etc. I'd appreciate any series lists or authors or even a personal list you've kept for a kid his age. Thank you!!!