Young-adult and teen books are huge moneymakers. It's at this age that people read the most. So writing a teen book can be not only fun but potentially quite profitable. There are a million stories you can write, either from personal experience or observation or as pure fiction.
Instructions
1. To come up with a good story idea, ask yourself: What do teens talk about, and thus want to read about? There are all sorts of topics--school, relationships, adventures, dreams, family issues, friendships, dating, trends and more. Also remember that all good stories have a likable protagonist or group of protagonists; an antagonist or group of antagonists; a need to be satisfied; a deadline or other time element; a conflict (usually between the protagonist's needs and those of the antagonist) and an overall message. Think of a way to work all of these elements into your story.
2. Outline your idea on paper. Write a one-page synopsis that briefly introduces the main details and provides clues to an ending. Ask a few teenagers to read your idea. It's best if you're able to ask teens of different backgrounds and both genders. (And readers you don't know personally will be more likely to offer an honest opinion.) Ask them for feedback about what would make them want to read the book, or what you could improve.
3. Develop your main characters. What are their hobbies, aspirations and views on life? Why do they need whatever it is they seek? Write out a page of details for each character. Then go out to the streets and listen to teenagers talk. Take a small notebook or tape recorder with you and write down keywords and phrases that strike you. Does a particular phrase sound just like one of your characters? Is this how you want your characters to speak? Remember, you get to choose how your characters talk, so give each of them a unique voice and point of view.
4. Outline your novel. It doesn't have to be perfect or exact, but it should provide at least a rough idea of how the story begins, escalates and ends. You should be able to follow the arcs of all of your characters in this outline, as well as the conflicts, inciting incident(s) and climax.
5. Write your book. Take as much time as you need. If you get stuck on character voices or plot details, go back to the streets. Listen to teenagers talk again and even talk to them. Ask them what they would do if they were a certain character in a certain situation. Do your research: Teens respond to stories that represent them properly.