And I fully realize that most people who will read this post either already know all this stuff or don't have children anyway or would never have a problem with anything their kid wants to read, but still I want to post it. It's easy to say that censorship is wrong and banning is bad, but it's also important to discuss how the issues that parents have with books can be handled in a beneficial way and mature way.
So You Don't Like Your Child/Teenager Reading That Book
Step One: Know what it is in the book that you think is inappropriate. Is it cussing? Drugs? Sex? The overall theme?
Step Two: Why do you not want your teen reading the book? Is it that you have value-based (religious/ethical) objections to it? Do you think your son or daughter isn't old enough or mature enough to handle the content? If it's drugs, sex, or cussing (three big topics) that are making you uncomfortable -- is it just that it makes you uncomfortable to know that your teen is reading something with that sort of content?
If your objection is based on a feeling of uncomfortableness, step back for a minute. Look at your teenager's environment and look outside of your own home: think about the school they go to, the friends they hang out with, extended family influences, etc etc. And then ask yourself if you're uncomfortable because you really think they'll be harmed by reading that book or if you're uncomfortable because you're just uncomfortable. Is it really an issue with the book? (Hint: probably not. Probably it has more to do with not wanting your teen to be subjected to unpleasant parts of life or not wanting them to grow up too fast or or or... anything else that doesn't really have to do with the story or how it's written.)
Step Three: Know what you're talking about. Ideally this would mean reading the book, but if you don't feel comfortable reading the book at least some good, in-depth reviews of it. You may have misinterpreted what you think it's about or, then again, maybe you didn't. Either way, it's good to know.
Step Four: Talk to your teen. Wait, let me repeat that again. TALK. TO. YOUR. TEEN. Tell them your objections. Have a conversation about why this book is unacceptable or inappropriate or whatever word you want to use. Decide together if the book is one that shouldn't be read in your family. If the book is one that your teen is reading for enjoyment, this is where it ends. Don't try to get the book banned from the school, please. If this is an assigned reading book that you have some real objections to then...
Step Five: Talk to your teen's teacher. Set up a meeting where you can discuss your concerns and decide on a course of action; maybe there's a substitute book that could be read instead.
A parent's course of action should not be to try and get the book in question taken out of school. What's too mature or inappropriate for one student is right for another student. Teenagers are people. They do not all come from the same environments or have the same maturity level or the same interests. Blocking a book from other students because you don't want your teenager reading it or you don't think any teenagers - or even any people, really - should read it is harmful to those teens who, maybe, would benefit from reading it. Sure, there are exceptions, but these exceptions are probably books like A How-To Guide for Killers or something like that. They're not the books on your ninth grader's extra credit reading list.