First you have to get a program that will take the songs from your iPod touch and put them on your computer. Then sync them to your computer. I've never used one of these programs, but a quick google search shows you can use a # of them. Icopybot is one of them.
You can't transfer the iPod music to iPad directly, you will need to transfer the songs from the iPod to iTunes and then sync them over to the iPad.
Well, there may be ways to do this directly in the future~