How to add customized CD artworks
Songs you purchase from the iTunes Music Store include album artwork. However, you can add your own graphics to any song or album in your library.
To do so, click the “Show or hide song artwork and video viewer” button in the lower-left corner of the iTunes window. You can easily switch between the selected song and currently playing song, by clicking the “Selected Song” or “Now Playing” text above the album art. To add album art to a song, select a song in your library, and then drag an image from your hard disk to the Artwork pane. The image will be displayed every time you listen to that song. You can assign a different picture to every song, or assign one picture to a group of songs.

You can also locate the song in iTunes library, right click on it and choose “Get info”, swtich to the artwork tab, then you can add artwork to the album or a single song.
