Blackcat, those descriptions of bodies are kind of shocking, but some kids aren't really fazed by that kind of thing, I think because they lack the life experience to really get the reality of it.
Also, "age appropriate" is so individual. DD6 somehow got me to tell her the whole story of the Unabomber, and didn't turn a hair. But I tried reading her A Little Princess, by Frances Hodgson Burnett, and by a few pages in she was sobbing hysterically in my arms and we had to stop. So this is, like, the ultimate YMMV issue!
There's no easy answer to this once they start reading independently and choosing their own material. It's good that you're keeping the lines of communication open with your DS and getting him to talk about what he's read. I suppose when there are serious red flags one might confiscate a book for parental pre-approval.
