There are, in fact, all sorts of levels of censorship. Beginning writers, especially the ones who are writing for children, are often concerned with what they "can" and "cannot" put into a book. Many writers I know are victims of their own self-censorship well before any reader gets an opportunity to object. And, honestly, there's no set solution for that.
Should you include swear words in your story? What about on-page sex scenes? How about politics? Religion? Violence? All good questions. There are some factors to consider:
- who is your target audience and will this turn them away, or make them pick up the story;
- what's the norm in the genre in which you're writing;
- does the material you're questioning move the story along in an integral way, or can it be replaced just as or more effectively with a different scene.
But ultimately only one person can decide - you.
It's your story. This seems like an obvious statement but trust me, there's at least one point in the writing process when you'll feel like the story has gotten completely out of your control, and that's usually when you start worrying about the atmosphere outside of your story instead of living inside it. Don't shy away from the controversial subjects. Your story will let you know what's needed. And if someone else doesn't like it, they don't have to read it. Or, better yet, they will read it and start a dialogue.
If you're really lucky, like Doctorow, your story will get banned and then everyone will want to read it. I know you're itching to read Little Brother now, so what are you waiting for?