Hunger Games resources
It is relatively dark in tone, violent in action, dystopian and libertarian in outlook. It does not endorse the violence or brutality of the Capitol governance. In fact, it is indirectly critical of both, along with contemporary culture's voyeurism and contemporary politics' willingness to sacrifice the marginal for the connected. It is well-written, a pleasure to read, not especially predictable (for books of this type).
It's a good read for adults-- and for teens and even pre-teens, especially if accompanied by some discussion with an adult. (Not all teens and pre-teens will like it-- and not all of them should read it, particularly if they will be sensitive to or provoked by the violence.)