Normally, when you put a CD in your computer, the files are stored in a format that is not easy to work with such as .AIFF , which also means that you can't edit the files. To overcome this problem, you can import the files using iTunes, which will produce an MP3 file.
Open iTunes from the Audio folder.
Insert your CD into the computer and open iTunes. You should be able to see all the available tracks on the CD in iTunes, but they will not appear in your iTunes library. Click the Audio CD icon at the top of the page. Select the tracks you would like to import. Click Import CD in the upper right hand corner.
A window will pop up for Import Settings. Be sure to select MP3 Encoder and Higher Quality. Then select OK.
Now, iTunes will import each track on the disc into an MP3 File. You can tell when a track is done by checking in your iTunes library. If it appears there, you have an MP3 file for that track.
If you don't see a list of your audio files on screen, then you can change that by going to View, clicking View Options, and then selecting Songs.
Example of what your library may look like after importing 1 track:
Locating Your Files
But where are these files? What if you need to edit them or use them somewhere else? Well you can find these files under Libraries ► Music ► iTunes ► iTunes Media ► Music ► [Artist Title]