If you want to sync your iPod to a new computer, or sync new songs without losing the music you all ready have, just follow these steps:
-
Connect your iPod to your computer
-
When iTunes recognizes your iPod, transfer iPod data to iTunes
-
Open you iPod from the left hand column of iTunes, under Devices
-
Choose Summary>Manually manage music and videos>Apply
This will allow you to manually add songs to your iPod without losing any music that’s all ready loaded.
Resources: eHow