I could fill a book (or at least Part II of this book) with all the great things you can do with iTunes. Following are some examples just to whet your appetite:
Listen to audio CDs.
Listen to Internet radio.
Store all the music you like in a single place so you never need to fuss with individual CDs again.
Search and organize all this music so that listening to exactly the music you want is just a matter of a few mouse clicks (and maybe a few key presses).
Create custom albums (called playlists) containing the specific songs you want to hear.
Create custom albums (called smart playlists) that are based on a set of criteria, such as all the Jazz music you have rated at four or five stars.
Use the iTunes built-in Equalizer to make your music just right.
Burn your own music CDs to play in those oh-so-limited CD players in your car, a boom box, or in your home.
Share your music collection with other people over a wired or wireless network; you can listen to music other people share with you as well.