Uploading song from iPod to computer

[Masaki-kun]

Umm... Literal as the title can be made. My iPod is full of songs much like a fruit is full of delicious juice. However, I can't figure out how to get those music files onto my computer so they can be worked with, backed up, ect. If my iPod goes, for example, I lose all the music I've collected since high school because none of it is backed up anymore. iTunes has a "transfer purchases" option but that seems to only work with purchases, not cd burns, legit free music, or, you know.