Sparknotes is a site designed to help high school and university native speakers of English in their studies. Many professors look down on such sites as being a kind of cheating, but for non-native speakers it is an invaluable reference in how to do summaries. You can look up pretty much anthing, but they specialize in literature. They have complete chapter-by-chapter summaries of the most popular books in high school. They even have some audio versions you can download and listen to on your mp3 player, and text versions for your iPod or phone. This is where books start turning into bits.
You might also want to try Shmoop. Teachers have liked Shmoop because they love literature, history, and poetry and would like students to love learning too.