[lordsmurf]

Still objects: NTSC still image menus are designed 720x540 (4:3) and imported that way into authoring software. The authoring software will convert it to 720x480 on its own. You need not help.

Motion objects: Video also needs to be edited 4:3 in the NLE (it should do that automatically). You need to encode the file out to 720x480 and import it that way into the authoring software. "NLE" is a non-linear editor, like Premiere, Vegas, FCP, etc., and is what you'd likely make motion menus in anyway.

This is more advanced: When combining stills/motion in the NLE, you may need to design the layers in Photoshop as 720x540. When done, merge the layers in the single alpha matte you'll need in Premiere. Shrink the image to 720x480. Import that with the video into Premiere. This needs to be done because the NLE actually has a pretty poor resize filter on matte images, so feed it something that's size-ready. It will preview 4:3 and that's all you need. Edit and save video as 720x480.

The "tv safe" areas found in authoring software is generally poorly done. You should notice it tends to put the overscan at even pixels sizes, but the overscan is half the height on top/bottom as it is on left/right. That alone can be a problem, which is why I use Photoshop for more precise design.

The way you drag guides out on Photoshop is by showing the ruler [VIEW->] and then clicking in the ruler and dragging out a guide. You may need to also enable showing the guides [(VIEW->]. Better yet, download the PSD I have in the instructions post at the top.