An excellent overview of DVD authoring here

Creating custom DVD Studio Pro Menu Patches

In DVD Studio Pro, under File, click Build and Format…

At the bottom, instead of selecting the DVD Drive, select Hard Disk. And save as a disk Image (.img file)

Once the disk image is created, from the Finder, right click it and select open with “Disk Utility”. Then in Disk Utility, select the image you just created and click burn.

If you have Toast or another burning program you could burn the DVD with the Video_TS folder. I prefer Toast over DSP as you can control the burn speed in Toast and not in DSP. Slower burn speeds=better compatibility (presuming you are using decent media.)

Apple’s guide to making DVD studio Pro menus using Photoshop files:-

http://www.apple.com/pro/techniques/photoshopintodvdstudiopro/