For each page you create in Dreamweaver, you can specify layout and formatting properties using the Page Properties dialog box (Modify > Page Properties). The Page Properties dialog box lets you specify the default font family and font size, background color, margins, link styles, and many other aspects of page design. You can assign new page properties for each new page you create, and modify those for existing pages. Changes you make in the Page Properties dialog box apply to the entire page.
Dreamweaver gives you two methods for modifying page properties: CSS or HTML. Adobe recommends using CSS to set backgrounds and modify page properties.