Let's talk about swearing in writing. Specifically, I want to talk about why I don't swear, but also why, if you do use curse words, you should do so only with great consideration.
We'll begin with why I don't swear in my writing. I don't think it's necessary. I'm also writing for young adults, and I never want to be accused of being a bad example to young people. I know swearing is everywhere in movies and on TV, and even in some of the other YA books they're reading, and if they read books marketed to older audiences, then there's an even greater chance that they'll be exposed to foul language. But that doesn't matter to me. I want readers to know that if they want a fun story that won't offend them in any way, they can read my work. That's not to say that I'll discourage anyone from reading any other book, but I know that, especially with younger readers, parents don't want their children exposed to curse words. When I start writing books for adults, I intend to find other ways of expressing the characters' frustrations.
Now, for swearing in other books. The Dresden Files books have profanity in them, but sparingly so. In fact, the first time Butcher used a cuss word in his books, it caught me off guard, and it made a real impact and got the point across fantastically. I've learned that, in writing, swear words stand out. It's not like speaking out loud where you can slip in a swear to emphasize your point and many people won't notice. Like I said, it's everywhere. When we hear it, we tend to ignore it. (I know many people don't, especially the older generations, but this is directed more toward the 40 and under crowd at the moment.) But when you read a page full of the "f bomb" it gets tiresome. A book I've been listening to on audio CD does that a lot. But even when I listened to it, I felt like the author just ran out of something clever and expressive to say, so he just filled in the blanks with "effing" this and "effing" that. I got bored.
I know, as writers we're supposed to portray people as they are, but that can be done without actually using the word the character is supposed to say. You can always just tell the reader, "Slade hit his thumb with a hammer and rattled off a string of profanity that he learned in his army days." That's not very creative, but it tells the reader that the character swears without actually swearing. If you continue to make points like that throughout the book, the reader is going to know that the character will swear when it suits him, and when you finally drop an "f bomb" in the climactic battle between the protagonist and his nemesis, the reader is going to sit up and say, "Okay, now it's serious!"
Back to my earlier point, as I listened to that CD, I thought about what it would look like on a page, and if I read that, I'd simply skip over that section of the dialogue. Not because I'm offended, but because it wasn't really going anywhere. They were excess words that didn't really get a point across. If the author had used half the swear words as he had used, I would still get a solid picture of the character without feeling like he stopped telling me a story just so he could prove that he wasn't ashamed to throw a few foul words into his book.
When you write, just keep that in mind. Save your swear words for when you REALLY want to make a point. I mean, just imagine how much attention the Pope would get if he threw out a swear word in the middle of a speech. Would you have any doubt that something was bothering him? On the page, they have that impact, for a while. Then they become just as tiresome as the same, flat descriptions of the paintings on the wall of an art collector's pillared mansions on the beeches and in the mountains. You don't really have to describe each one in detail. Just do it once and we'll get the picture.