If you are writing a non-fiction book, you must research and know your material. You can write from your own experience or from interviews with experts in the field. Fiction books require research as well. It is helpful to understand the market for the genre in which you are writing. Visit a bookstore and see which books are selling in your chosen genre. Familiarize yourself with some of the books to gain a sense of the styles that are popular with readers. Do additional research in history, science or cultural norms to effectively create believable characters and scenes.
Write a brief summary of your book. In a few paragraphs, state the theme and goals of your book. For fiction, give the basic plot points so that you are aware of the setting, the main character's identity, his struggle and how he will change and adapt in order to accomplish his goals. Many publishers want to see a book synopsis as they consider publication, so this is an important step to complete.
Fiction requires the development of characters and plot. Novelist T. L. Higley suggests creating a character profile for your protagonist, antagonist and a few of the minor players. List their physical features, personality quirks, strengths, weaknesses and anything else that defines them. Keep the list handy in a notebook and refer to it as you work. Writing about a character's blue eyes in chapter 11 is no good if you've given him green eyes in chapter 12. In another section of the notebook, map out a basic plot line. Set the scene, introduce the characters, create a problem or conflict and then figure out how to resolve it.
Once you have a basic plot, expand your ideas into an outline. Flesh out details about the setting. Add information about conversations that take place or actions that are taken. For non-fiction works, create a map for the points you will address to thoroughly cover the topic. Make sure that all questions someone might have will be answered in the text.
Write. Many authors recommend setting a specific time to write each day and sticking to it. Don't worry about making it perfect. Simply get the words out. If you find that you need to do more research, make a note to add the information later, but keep writing, so that the creative process is not interrupted.
Edit and rewrite your book to make it clear and polished. Author Jeanne Marie Leach tells beginning writers to make several passes at the copy. Read once for ease of readability, once for content consistencies, again for clarity in how language is used and finally for grammar, punctuation and spelling. Reading your work out loud is one of the best ways to check for errors and unclear passages according to author and editor Audrey Owen. Hearing your words is different than reading them, so you can catch many mistakes by utilizing this step as you prepare your manuscript for publication.