Adding Video from the Hard Disk
You can add video from the hard disk in any of these ways:
With the Video tab selected, drag video files from any location on your hard disk to the Video content area.
With the Video tab selected, click the Add button. The Open dialog appears, where you can browse your hard disk for video files. Select the files you want to add, then click Open.
Each video file you add appears as its own row in the Video content area, with each row appearing as a button on the menu on the finished disc. For information about how this will look on your TV in your final video disc, see Understanding Menus and Buttons.

See Also:

Adding Video or Slideshows to a Video Disc
Adding an iMovie Project to Toast
Adding Photos from the Hard Disk
Adding Photos from iPhoto