2 devices on 1 itunes?

*How to use multiple iPods with one computer*
The Apple support document How to use multiple iPods with one computer suggests a number of ways. I use method two (Sync with selected playlists) with a slight twist. Rather than regular playlists I set the grouping field to indicate which users should receive which tracks and create smart playlists based on the content of this field.

e.g.
"Alice's Tracks" is "Grouping contains Alice" + "Kind contains audio"
"Bob's Videos" is "Grouping contains Bob" + "Kind does not contain audio"
Tracks that both Alice & Bob want on their iPods have the grouping set to "Alice/Bob"
etc.

I currently manage our family's five iPods using this system, each getting a different selection to suit their tastes and the capacity of their iPod. An advantage of using the grouping field is that it is stored in file tags (for non-wav audio files anyway) so that it is relatively easy to recreate the playlists should the iTunes library get trashed. Also useful if you move files about manually as playlist membership is preserved when you delete & re-import the tracks.

tt2

You can sync as many devices as you like to one library/computer.

Plug it in and select what you want to sync to that device and sync.

Do the same for each device.