iPhones are very popular and keeping the world of telephony buzzing. To manually manage music and video in iTunes, your iPhone needs to be connected to your PC. Select your iPhone in iTunes and click the on summary tab. Choose Manually manage music and videos, then click Apply. To add items to your iPhone drag the content you want from the iTunes library to your iPhone in the sidebar. iTunes immediately synchronizes the content. To remove items, select the iPhone icon, delete the content you wish to from the library. Deleting an item from iPhone does not remove it from the iTunes library; but deleting it from iTunes will remove it from the iPhone when you synchronize the next time.
Is there an advantage in synchronizing my iPod manually?
Choosing "Automatically sync when this iPhone/iPod is connected" is the most convenient option, as long as everything is going the way you want. This option ensures that any change in your iTunes library will be replicated to your iPhone or iPod when you connect it with your iTunes library.
But, if the contents of your iTunes library were damaged or deleted for some reason (e.g. iTunes reinstall, re-installation of your operating system or break down of your hard drive), the automatic update may pose a risk. By synchronizing your iPod or iPhone with a damaged or deleted iTunes library you risk erasing the entire contents of your iPhone/iPod. In case of a problem or if you have doubts about the contents of your iTunes library, make sure you choose the "manually manage music and videos" mode to prevent data loss.
Where to set up the "manual iPod management"?
Open iTunes and connect your iPod/iPhone. Choose your device in the left column and select the first tab called "Summary". Now check the option "Manually manage music and videos" and confirm with "Apply". You are now managing your iPhone or iPod contents manually and don't risk to automatically synchronize your iPod and iPhone with an empty iTunes library.