After watching the most recent Hunger Games film, (which is brilliant by the way) I wanted to go back and re-read the series, so I picked up the third instalment The Hunger Games: The Mockingjay. So far, the films are only up to the second book, so if you want to get ahead I recommend you get a crack on with the books.
Unusually, with The Hunger Games series, the films are just as good as the books.
I'm not really one for reading YA fiction (although I do like to periodically re-visit Harry Potter and think His Dark Materials is amazing) but The Hunger Games is, in my opinion, a successful crossover book that appeals to both adults and teenagers. If you're stumped for buying a book for ages 11+, I'd highly recommended this series. It has a strong female protagonist, and promotes the values of bravery, compassion and resilience.
I don't want to give away to many spoilers so just a brief summery of the series:-
In a dystopian future, twenty-four tributes between the ages of twelve to eighteen are selected at random
to enter the annual Hunger Games, in which they must fight to the death until only one survives.
The Hunger Games: The Mockingjay is, I think, the weakest of the trilogy, as the action takes place outside of the Hunger Games arena. It is however, still a tense and enjoyable read and a satisfactory conclusion to the series.