use a usb cable that it comes with. If your using windows XP you will need to install the drivers for it. If windows 7 or Vista you should be fine. Please note, that lots of game dont work with the 360 controller....
No, that does not work.
For wireless xbox 360 controllers you need a wireless adapter for your PC
for wired Xbox 360 controllers they should work, just plug them in.
for Original Xbox controllers you will need to either buy or make an adapter to change the connecter to USB, then it will work.