High school students don't appreciate being talked down to, just ask them. They've got a good idea on how their life should operate and how better everyone else could operate their own, again just ask them. We can joke about the cock sure nature of teenagers (especially because we were the same exact way) but the best way to enlighten them is to show them. The Road is most definitely mature subject matter. This isn't a book that holds someone's hand and tells them that everything will be okay. It's a novel that takes someone's hand and drags them some place unsuspecting and then challenges them to survive. There's a line in all art on what is mature and what maybe pushes that boundary too far for younger minds. This is not a book that's easy but it never crosses the line of too explicit. The Road isn't in the apocalypse business -- McCarthy simply ignores the easy subject of glorifying our downfall like so many other authors before and after him. Instead, he says, "this happened and it was bad, now how do we carry on?" It's a dark subject but there's light there if you choose to see it.