Once the first sync is complete, you can make some choices about what content you want to sync and what you dont. Click each of the tabs at the top of the window to change these settings you may not want to sync all songs, or may want to exclude podcasts, or add contacts, etc.
Be sure to click "Apply" at the bottom right-hand corner of the window to make the changes active.
The changes that you make here - such as deciding not to put some songs on your iPod - will take effect the next time you sync your iPod.
To learn more about some of these options, see:

