I have successfully used my Clip Sport to organize and play audiobooks copied from CD’s (public library) and from Overdrive service (also public library). Maybe take a look at this long discussion in the SanDisk Forum.
http://forums.sandisk.com/t5/SanDisk-Clip-Sport/Audiobooks-do-not-show-up-properly/m-p/355309#M3090
Also, there are a few common complaints by new Sport and Jam owners when attepting to use these players for their audiobooks.
1. Slow fast-forwarding speed to advance to a distant playback point in a long file.
2. Only one “resume” point saved per audio file (Books mode).
3. Books mode does not accept playlists.