Well, the ZR20 uses firewire for transfers. As for how it works, you load up Adobe Premier (or similar program), and load the video from the camera. You can also yuse the program that comes with the camera, but it sucks.
The ZR25 and above series use firewire and USB. USB is mainly for the use with the memory card and quick transfer's. The firewire is for the DV transfer, since its much faster.
Most programs you use can identify the camera you are using, since you install a driver on your computer with the included disk. From there, its pretty much just point and click and transfer. That is until you get into video editing.
