You need IEEE1394(Firewire card) to download the Digital video to the computer from your DV.
See if you have this interface built-in in your motherboard or not.
If not, the card is about $70, I think.
USB on most DVs are to download the Digital camera pictures.
If you are using some of the Sony DVs, you might be able to download the Digital Video through it.
Then you probably need some softwre which can edit and compress the video into MPEG-1(for VCD) or MPEG-2(For DVD). Then use nero to burn it into CDR/DVD-R.
Hope this helps.