I'm not sure of the export options in Elements, but if you can, use Adobe Media Encoder or otherwise export as a 'multiplexed DVD-Video MPEG-2 with PCM audio' - Or, you can export as an uncompressed AVI and let your DVD authoring software do the transcoding.
The safe guides are at 90% and 80% of the frame size (I think). The larger guides define the Action Safe Area and the smaller guides define the Text Safe Area.
For best image quality, save your images as PSD (Photoshop) or TIFF with LZW compression, both are lossless image formats.
There are other issues with using square pixel images in video, maybe you don't want to worry about right now.
But if you do, you might want to correct the aspect ratio of the images.
If you are creating an NTSC full screen DVD you should open the images into a 720x540 file, than resample the images to 720x480. The image will appear to be vertically squished, but will display correctly when viewed as a DVD.
Also, if the video will ever be displayed on a CRT you should 'deflicker' the images...
http://www.handcranked.newinelabs.com/assets/Adobe_Photoshop_Action_-_Encor...
Finally, you might want to add the Broadcast Color filter to the entire sequence, but this would also only be necessary if it will be displayed on a CRT.
Vince