Sidebars
Sidebars are pieces of content (text/images) outside of the main content area of a page.
Sidebars are only used on pages where the template for the page has been specifically set up to use them. The actual usage of the sidebars will depend on how the templates are set up, for instance they may appear to the side of the main content on a page or they may as pop-up windows. Sidebars also have their own templates for changing their appearance.
Sidebars can be grouped into categories much like pages can be grouped into chapters.
Sidebars have properties and content much like pages do. Editing properties and content works just like it does for pages.