How do I copy music purchased from the iTunes Music Store to a new iPod?

I recently purchased a new 60gig video iPod. I am trying to copy all of my iTunes music library to the new device. However, the music that was purchased from the iTunes Music Store will not copy. I receive an error message saying that some of the music in my iTunes music library connot be copied because it is not authorized to play on the iPod that is connected. But now that I have the new iPod I need to get that music to the new device. What do I need to do in order to get the iTunes purchased music to be able to be copied and played on my new iPod?How do I copy music purchased from the iTunes Music Store to a new iPod?
Don't panic. All you need to do is authorise the songs from your iTunes account.