There are a couple methods for creating the child pages of a book - from the current Book page and from the Create content page.
From the Current Book Page
While viewing the Book page that you just created, click the Add child page link.
See Create a Book for instructions on entering content in the Title and Body fields.
Book outline
Click on the Book outline tab.
Book: The Book option is already selected with the previously created Book page.
Parent item: The Parent item option is already selected with the previously created Book page. If desired, select the Parent item in the book for the new Book page. For example, if you would like the Book page to be a child or sub-page of the top-level page Book, then choose Book as the Parent item.
Weight: The Weight drop-down is used to set the order of Book pages, however using the Books section is a much easier way to sort book pages on the website. To change the order of your Book pages, see the section on Managing the Book Outline.
From the Create content page
From the admin menu, select Content - Add content. On the Add content page, click Book page to add a new Book page to the website.
See Create a Book for instructions on entering content in the Title and Body fields.
Book outline
Click on the Book outline tab.
Book: From the Book menu, select the Book the new Book page should be a part of.
Parent item: Select the Parent item in the book for the new Book page. For example, if you would like the Book page to be a child or sub-page of the top-level page Book, then choose Book as the Parent item.
Weight: The Weight drop down is used to set the order of Book pages, however using the Books section is a much easier way to sort book pages on the website. To change the order of your Book pages, see the section on Managing the Book Outline.
Menu settings
Since the child page is part of a Book and will automatically be added to the Book outline, there is no need to assign a Menu link title to the Book page.
For information on Revision information, Authoring information and Publishing options, see their respective instruction pages on this website.
Save
Click the Save button when you have completed entering the child page content.