HowTo: Convert MP3s to Audiobook

Many iTunes users will have audiobooks in mp3 format, ripped from CDs or downloaded free. The problem with these is that iTunes treats them as music files and includes them in the Party Shuffle playlists. This tutorial will show you how to make iTunes treat them like Audiobooks, so you can keep them separate from your music and even adjust the play speed.

The only difference between audiobooks and standard m4a music files is the file extension - audio books are named '.m4b'

To convert your audiobook, first you need to ensure that they are in m4a format. Select one of the files in iTunes and hit cmd-i to bring up the inspector. At the bottom of the information window you can see the files path and name, including the extension.

If the extension is .m4a, your files are ready for renaming, and you can skip this next part. If they're mp3, you'll need to convert them:

1. Hit cmd-, (comma) to open up iTunes preferences. Navigate to the advanced tab and select the importing button. 
2. Change the drop-down menu Import Using: to AAC Encoder and change the setting below to Spoken Podcast. Now close the preferences window.
3. In iTunes, select all your audiobook files you want to convert. Right-click them and choose 'Convert selection to AAC'. (This process may take a while)

Now locate your m4a files using Finder ([home directory]/Music/iTunes/iTunes Music/...) If you've converted them from mp3 you can delete the original mp3s to save space.

The final step is to rename them all from .m4a to .m4b files. You can use this workflow file to do it for you (open up the file and hit run in the top-right hand corner of Automator), which asks you to select the files and converts them all in one go. 

Once you're done, drag all the files into iTunes, and they should now be listed under the Audio Books panel. (You may have to delete the originals from your music library)

For the reference, free audiobook sites include LibriVox, Audio Books for Free, Books Should be Free or, for the biblically inclined Faith Comes By Hearing.