iTunes 10 for Windows: Import music and video already on your computer
To add media from MusicMatch Jukebox or Audible Manager to your iPod, iPhone, or iPad, you need to first import it into iTunes.
Here are ways to add items from your computer to your iTunes library:
Drag a file or folder from the desktop to the iTunes window.
If you add a folder, all the files it contains are added to your library.
In iTunes, choose File > “Add to Library,” locate a file or folder, and then click Choose.
By default, adding items to your iTunes library places a pointer to each file in the iTunes folder; the original file remains in the current location. For information about copying files to the iTunes folder instead of referencing them, see Copy files to your iTunes folder automatically. If the file is an unprotected WMA file and you have Windows Media Player Series 9 or later installed, iTunes makes a copy of the file and adds it to your iTunes library. The original WMA file remains unchanged. You can’t add protected WMA files or protected WMV files to iTunes.