get MPEG Streamclip as already suggested. you can edit out out the commercials in MPEG Streamclip, no need to export to DV unless you want frame accurate editing, but that will mean hours of re-encoding and a loss of quality as a result. MPEG Streamclip can edit on the I-frames, about 2 I-frames every second, which is fine for cutting commercials. ffmpegX or sizzle, both freeware, will author a DVD. Toast, not free but worth every penny, will author and burn.