I don't get the Amanda Knox murder trial........?

I am so lost! How did the chick Meredith die? Was it just 2 people apart of that? WTF?! I'm sorry, and don't call me dumb or anything but I don't really watch t.v much. I've heard about this trial about 4 times on CNN but I never pay attention to the news. Can some PLEASE break this down for me?