The Hunger Games trilogy is set in the future in a place called Panem, which was once North America. The Capitol is surrounded by 12 districts, each which serves the needs of the Capitol. The districts are forced to compete in the annual Hunger Games as a punishment for past rebellion. Every child between the ages 12 and 18 is required to enter their names into the drawing, and those who are chosen fight in a televised battle to the death with only one winner. The story follows Katniss as she becomes part of the games. To say anything more would be giving away plot that I think could spoil the trilogy. Be careful about reading long reviews because I think that this story is better experienced if you don't know too many of the twists ahead of time.
I enjoyed the first book the most, however, the trilogy as a whole is excellent. The violence in the last book is the most intense, and I'm still not sure what I think of some parts of the ending. However, I think the author brings it all together in a way that makes sense for the story. If you are a big chicken (like me), these books will probably push your comfort zone, but are well worth it.