ipods make things difficult on purpose.
you cannot use the drag and drop like you would add files to a removable harddrive, to add your songs. you MUST use a compatible program such as iTunes to copy your music to your device. and even when the songs are copied onto your iPod, you cannot open My Computer and click on the removable iPod icon and see your songs. It will look like nothing is there. you must use iTunes software, (another example is musicmatch) to view and add songs to an iPod.
on another note, you cannot take songs from an iPod and transfer them to a computer. (Say you wanted to go to your friends house and transfer some songs from your iPod to his computer, you cannot do that
). Although there is 3rd party software out there that allows you to.