For effective storage management of your audio books in your iPhone, you should use the playlist option for limiting the storage of audio books to a desired size. Only the specific playlists should be synced to your iPhone, instead of the full contents of your audio books library. These playlists help you develop a groomed subset of your audio books. In this manner, you would be able to control and set limits for the dedication of the storage for audio books in your iPhone.

You should initially create a new playlist with a specific name. For example, the name could be Kitabebooks-6GB. This playlist would track only the Kitabe.com books that had been previously checked by you. These books would be the ones that you had not listened to till now. Thus, you would be creating a playlist in your iPhone that is limited to 6 GB of Kitabe.com audio books that you had not listened to so far.

Once you had listened to a particular audio book, you immediately uncheck that one in your iTunes, removing that book from the present playlist. Now, other audio books that had been checked would automatically get synced and loaded. This continuous removal and replacement by checking and unchecking is the best way of effectively managing your large collection of audio books through your iPhone. You could think of a few more methods for iPhone management of audio books.