Publishing begins with authors, sometimes known as writers, and their ideas; or with a book producer, agent, or editor who identifies a topic that demands a book. Writers of trade books typically hire a literary agent to help them present their ideas and finished manuscript to interested publishers. Approximately 123,200 authors and writers and 118,300 editors were employed in the United States in 2018, according to the Department of Labor.

There are many types of books published; currently the largest market share is in trade books, textbooks, and technical and professional books. A publishing house may produce books in all these categories or just in one category.

Textbooks are books that are designed to be used in schools, and they are divided into such categories as elementary school, high school, and college. When writing textbooks, publishers must take into account such factors as subjects that are emphasized in school curricula, subjects that are taboo, and the reading ability of the students in the targeted age groups. In recent years, for example, textbook publishers have adopted a more multicultural approach to historical content that gives more attention to the accomplishments of women and people of color than was included in past decades.

The category of trade books encompasses most of the books that people commonly read, including short and long fiction; poetry; and nonfiction books on contemporary issues, history, religion, art, music, and a host of other subjects. Large publishers often produce trade books on a wide variety of subjects, but smaller firms may specialize in one or a few subjects.

Technical and professional books are, for the most part, specialized works intended for relatively small segments of the population. Because they are produced in much smaller numbers than are trade books, technical and professional books are usually expensive. Medical students and doctors need books on medicine, law students and lawyers need law books, and scientists need books that address their specific areas of interest.

Another area of technical publishing is that of reference books. Reference books are usually designed to make the location of particular pieces of information as convenient as possible. They are not designed to be read from cover to cover. When most people use a dictionary, for example, they want to look up a particular word rather than read the entire dictionary (although some people do like to increase their knowledge of words by reading through dictionaries). In addition to dictionaries, encyclopedias and almanacs are also examples of the types of reference books that are published.

Once a manuscript is accepted by a publishing house, it goes to the editorial department. Headed by an editor in chief or editorial director, the editorial department evaluates manuscripts, revises written material with the writer, and prepares the manuscript for the production staff.

After a manuscript is revised by the author and approved by an editor, it is turned over to the production department. Production is the division of publishing that takes a manuscript and makes it into a book—usually with the help of page-layout programs. The copy editor makes corrections to the text. This includes correcting the spelling, grammar, punctuation, style, and general readability of the text. This can either be done by writing on the typed pages or, as is now most often the case, by making the changes to the text on a computer.

Typesetting is done by a computer that generates the pages that will print in the book. The pages are read by a proofreader who will catch any problems with the text or with coding. For e-books, typesetting is replaced by a digital conversion and coding process that conforms the book to .epub, .mobi, .pdf, or another e-book standard.

Once all the pieces of the book are in place, the book is ready to be printed and published. The marketing department, the acquisition department, and the production department work to determine the number of books that will be printed, the size, the binding style (hardback or paperback), and other details. Today this also includes an e-book edition. Although no print run must be set for e-books, publishers must navigate other factors such as pricing and different e-book formats. Many small and some major publishers are also experimenting with e-book-only formats.

While a book is in production, the promotion department hires advertisers to schedule space in magazines and newspapers, works out cooperative advertising with retailers, and produces point-of-purchase material for use in stores. Direct mailings to promote or sell the books are also arranged. For potential bestsellers, the staff may also arrange for newspaper, radio, and television releases and set up interviews for authors in all of those media, with the intention of keeping authors in the public eye.

In the United States, publishing companies vary in size from offices with only a handful of employees to corporate giants employing a thousand people or more.

Other areas of publishing include greeting cards and music publishing. Greeting card publishers employ artists, writers, and designers to produce cards for holidays and special occasions, and they are increasingly working in digital formats as well as prints. Music publishers publish the music to songs, rather than actual recordings, and control the rights for music professionals to perform those songs.