How do you import your iPod's music library into your iTunes library?

Answer 1

From official Apple manuals:

Adding iTunes U Content to iPod classic

The settings for adding iTunes U content to iPod classic are unrelated to the settings for adding other content. iTunes U settings don't affect other settings, and vice versa.

You can set iTunes to automatically sync all or selected iTunes U content, or you can add iTunes U content to iPod classic manually.

To set iTunes to update the iTunes U content on iPod classic automatically:

1 In iTunes, select iPod classic in the device list and click the iTunes U tab.

2 In the iTunes U pane, select "Sync iTunes U."

3 Select the collections, items, and playlists you want, and set your sync options.

4 Click Apply.

When you set iTunes to sync iTunes U content automatically, iPod classic is updated each time you connect it to your computer.

If "Sync only checked songs and videos" is selected in the Summary pane, iTunes syncs only items that are checked in your iTunes U and other libraries.