photoartist

When making EXE files, I know what size to make my still photos.....PowerPoint Size (1024x768) @ 72 dpi. But.... When I make a DVD that will be played on a TV, what size (in inches or pixels) and what resolution, (dpi) should I make the still photographs? Will JPG's work OK or should I use TIFFS? What is the ratio - proportion - of a TV? If a picture is 1024 pixels wide, how tall would it be to fill the screen with no clipping? Thanks !!! John