Now that you have songs organized in playlists in your iTunes library, you'll be able to take your songs into other iLife applications. For example, add your favorite song to a slideshow or home video. Check out the iPhoto and iMovie HD tutorials to learn how.
Find Music on the iTunes Music Store
Your iTunes Music Store Account
Find Videos on the iTunes Music Store
Find Audiobooks on the iTunes Music Store
Authorizing and Deauthorizing Your Computers