Adding Web Pages
To add a page to your map, drag a box from the toolbar (or from a specialized web layout library) and drop it on the connector. When a shape or line is moved near a connector, Link Points appear. The outline of the moving object jumps to the closest link point, showing where it would connect if you released it. Releasing the mouse attaches the object to the connector at that link point.
Drag as many shapes to the connector as you like. The connector will keep expanding to accommodate your shapes.

Start your site map by drawing the first level of pages under the home page. For example, if there are four main categories under your home page (products, support, store, about us), drag and drop until you have four boxes on the first connector line.

Changing the Connector's Shape
You can change the connector's shape by right-clicking on the connector line and selecting a style from the Change Connector Shape pop-up menu.

You can continue to change the shape of the connector until you find the one that suits your needs. The Flip command under the Arrange menu can also be used to create mirror-image variations.
To learn how to rearrange boxes already attached to a branch, read the org chart tutorial here.