In order to write an effective how-to book, one must first understand their purpose for writing it.

When certain goals seem to remain hopelessly unattainable due to the absence of common sense, stock knowledge, or easy instruction manuals on how to achieve them, well-written "how-to" books offer deliverance by providing a chance for their realization.

While writing effective how-to books can boost a writer's ego or provide opportunities for profit due to an increased market demand, such reasons are only secondary to its core purpose, which is to educate readers and help make a difference in their lives. Alternatively known as self-help or "do-it-yourself" books, "how-to" books are intended to assist their readers in working out their own problems - from operating a machine to boosting their self-confidence.

In general, a "how-to" book describes a process. It is written mainly for the purpose of teaching or instructing readers to perform certain actions in order to achieve an end result. A "how-to write a how-to book", therefore, specifies the steps needed in order to create a book which teaches exactly that. In other words, a how-to book does not aim to show what the writer knows, but to show others the way to know something.