Outlines are used to organize the thoughts of the author so that they can write a well planned book. Book outlines are also created so that a publisher or agent can get a feel for a non-fiction book before the author writes it. The execution of the outline can sometimes make or break a book deal.
It can take a few day to a few months for an author to create a book outline. It all depends on how complicated the book is and how the author works. Some authors create the outline while they are writing their book.
There are many different types of outlines. Some authors use the general outlining rules taught in school that use the roman numeral system and the alphabet to organize ideas into categories and sub-categories. Others write down the name of each chapter with a paragraph or two about what will happen in that chapter. Another strategy is to write scenes on index cards, arranging them and rearranging them to come up with the best plot line.
The type of outline an author chooses to write depends on his needs and style. Organized writers tend to like the roman numeral type outline, while writers that like to brainstorm find the index card method handy. If a writer is submitting an outline to a publisher or agent they should follow the guidelines set by the company.
When used properly, an outline can guide a writer back on track when they face writer's block or if the story is going off on a tangent.