How do I authorize songs in my iTunes library?

How can I put songs on my ipod that aren't from itunes and from a different computer than the itunes library?

• I have a bunch of songs that are downloaded just as mp3's on a computer. On another computer, I have my itunes library, so is there a way to put those mp3's into my itunes library? One Idea- could i put all of the mp3's on an external hard drive (which im guessing is a memory stick/thumb-drive thing right?) then put that on the new computer, BUT where would i put the songs from the external hard drive so they go into my library, if this even would work thank you so much for any of your answers :)

• Answer:

  just put your songs in your usb then plug into your other computer then drag the songs from your usb into your itunes libery or y not hook your ipod into your other computer?