I think you just plug it in via USB. It should be detected automatically by Windows and be accessible as a storage device. I thought I read something where you couldn't use FireWire from a PC (only from a Mac), but maybe that was just on the first-generation ones?
You need to use a program that knows how to load music files onto it if you want them to be accessible from the iPod itself. There are a few third-party alternatives to iTunes, but I'm not real familiar with it (since I don't own one). I'm sure some searching would turn something up.