How to Convert an .AIFF to an .MP3 using iTunes

First you need to open up iTunes. You can find the application in the multimedia folder. Click the folder and chose iTunes from the pop-up menu (as seen in the picture) or double click on the multimedia folder, find the iTunes application, and double click on the icon.

Shows location of iTunes.

If you haven't opened iTunes on the computer you're on before, you may be asked to agree to the Software License Agreement. Go ahead and click agree, yes, next, ok, until you see the Done button - click that and then iTunes will open. You may have to click OK once more, and then it may tell you that a new version of iTunes is available and ask if you want to download it - you don't, so click no. When you're done, you will see this come up:

Shows what iTunes interface looks like.

You can drag and drop your music file from the desktop into the iTunes and it will appear listed there. As you can see here my intro 1.aiff file is in iTunes.

Shows what a file looks like in iTunes.

If you right click on the file you'll see this drop down menu. You'll notice there is a "Convert Selection to AAC" option, but we don't want AAC, we want MP3, so don't choose this option. We need to change the preferences first so we can make the MP3 option available there.

Shows that the wrong option is originally set.

Going into the topmost menu -under the iTunes heading - there is a Preferences option: click that.

Shows where 'preferences' is located.

The Preferences box should pop up. Select the "General" tab,
then click on the "Import Settings" button.

Shows what the 'importing' tab looks like.

With the Importing option selected you'll see you have an option that says "Import Using:" followed by a drop-down menu. Click on this box, and pick MP3 Encoder. For the setting dropdown box set it to "Good Quality". Then hit OK.

Shows how to select 'import using mp3 encoder'.

Now right click on your song again, and you'll see the option "Convert Selection to MP3". Select that and watch iTunes convert the file into an MP3.

Shows how to then convert the file to an mp3.

Once it's finished, it's hard to tell which one of the 2 files it is, since the extension isn't listed. This isn't a big problem, however, because you can right click and select "Get Info" to find out more about what type of file it is... (see picture below) ... OR...

Shows  how to look at the 'get info' information.

you can right click on it and select "Show Song File" which will take you directly to the folder the file is located in. Because it takes you directly to that folder, you can just look at the extension there and see if that's the right file. (If it's not then obviously go back and pick the other one.) Then you can drag and drop or move your MP3 file wherever you want.

Shows how to find where the file is located.