I was assigned this book for my English class. I got about a hundred pages in on the first night. The next morning I asked a friend whether or not it got any better. The first hundred pages were so disturbing and depressing that I was prepared to just stop reading and take a zero, even though I was already not doing so hot in that class. But he told me it got better. It did get a fair amount less disturbing, but only marginally less depressing. 
 To be honest I don't think this is an appropriate book to assign in a high school English class. I'm not saying to ban it, I mean by all means keep it in the library and available, but don't force students to read about freaking (view spoiler)[twelve-year-old boys getting gang-raped (hide spoiler)] because that's a great way to give a whole graduating class emotional problems, as well as getting the school sued. 
 Overall verdict: Worth reading. I didn't think it would affect me very much after I first read it, but I find I think of this book rather a lot.