Just a question on DVD

Depends what audience you are aiming for.

NTSC has to have one of the following resolutions.

720x480
720x486
704x480

NTSC must also run at 24 or 29.97 frames per second.

Of course, any DVD/TV combo that can display NTSC will be able to display any of those combos.

PAL resolution must be one of the following

720x576
704x576

It must also have a frame rate of 25fps.

I'm not too sure about SD and HD formats, but I don't think you would be using that anyway :)

I'm not sure exactly what you mean by 'What format is DVD?'. Could you explain it a bit better? If you mean what video encoding must be used, then it uses MPEG-2 (file extensions are usually .mpg .mpeg. mpv. m2v).

I'm trying to find out what would be the best resolution to render my short flim out at.

If you are just after PAL authoring (Australia standard), then either 720x576 or 704x576 will be fine. Using the lower is probably best as you wont really notice those extra 16 vertical lines on your TV. You may on a comp screen though :)

Thanks for the help I will be rendering it at 720*405, and then adding letter box black at the top and bottom for different fromat (PAL/NTSC.)