My advice is: don't. Let the display device scale the image. By upscaling to HD, you'll just increase the filesize massively and the end result is almost certanly not going to be as good as letting the TV do it (especially if it's a Samsung; sweet!).

If you must, and assuming your input is 720x480 NTSC DV, you'll want to crop to 704x480 (this eliminates the nominal analogue blanking area; don't worry if there are active pixels there, they were never meant to be seen). Then scale up to 1440x1080 and add borders to 1920x1080.

The important thing to note is that DV doesn't have square pixels, but HD does.

DE