How to manage two iPods on one computer or transfer music between iPods?

Manage more than one iPod on the same computer

Method1
Create multi accounts on one computer, one account for each person to login OS and sync his/her iPod with iTunes.

Method2
Set your iPod to “Manually manage music and video”, and then create a new iTunes playlist for each iPod that contains all the music that you want to send to that particular iPod.

Transfer music between iPods

Method1
As for transferring music between different iPods, you need a special application to do that, I have tried a program named iPod2iPod, it can successfully transfer my friend’s iPod music to my iPod, and here is a guide about it: http://www.top5soft.com/tutorial/how-to-transfer-music-between-iPods.html

Method2
You can transfer music from iPod to your computer, and then re-add it to your iTunes library and sync it to your iPod.