Ipod nano won't sync mp3 audiobook

Assuming you have an Audible membership/subscription, you can download audiobooks to your PC and then connect the player to the PC and transfer the audiobook files from the PC to the player.

Hi there PatAccording to the user manual for the ipod nano 5th generation you can add audiobooks. These directions are directly from the manual
In itunes, select ipod nano in the devices list and click on the music tab
Then select Sync Music, and then do one of the following:(a) Select "Entire music library"(b) Select "Selected playlists, artists, and genres," and then select Audiobooks (below Playlists).Click Apply.The update begins automatically.Hope this helps.

Hello,

follow the steps below:

1. Put a CD of your favorite music into your computer, and then open your Zune player. Click on the music that you want to copy.
2. Click on the "Rip" button, and then save your music with any of the following file extensions: .wma, .wmv, .mp3, .jpg, .mp4, .m4v, .m4a, .m4b or .mov. The ability to play music in all of these formats is one of the features that make Zune such a superior digital player.
3. Plug your Zune player into your computer using a USB cable, and then the Zune software will automatically import all of your selected music into the player. Set the "Sync" option to "Default" so that all the music in your directory will install in your Zune player whenever you plug it into your computer.
4. Purchase music online by either buying each song individually (usually for about 99 cents a song) or buying a membership to a website where you get unlimited downloads. You automatically get a membership to Zune Marketplace when you purchase Zune, and you can get unlimited downloads there.

I hope the above steps will help to solve your problem.

Good luck

here's the website: http://support.apple.com/manuals/#ipod
you can download the user manual from there.

That is the problem. iTunes will only allow you to put audiobooks in that section if they were bought from the iTunes store. It's very annoying, but i suggest just making a playlist to hold all the files. iTunes doesn't let you set the type as "Audiobook" for files.

First I would suggest you make sure the iPod is connected correctly, and that you wait until the iPod has finished updating.
If you are sure of that, you can always restore the iPod to it's original settings.
(I would also suggest that you are using the most updated version of iTunes)
But before you restore your iPod, there are a few steps you can take to try and fix this problem.
If you can’t download a song or other item to iPod nano 
The song might have been encoded in a format that iPod nano doesn’t support. The 
following audio file formats are supported by iPod nano. These include formats for 
audiobooks and podcasting: 
 AAC (M4A, M4B, M4P) (up to 320 Kbps) 
 Apple Lossless (a high-quality compressed format) 
 MP3 (up to 320 Kbps) 
 MP3 Variable Bit Rate (VBR) 
 WAV

The most common is to reset the iPod. To do this:

•  toggle the Hold switch on and off ( Set it to hold then turn it off again) 
  
• Then press and hold the Center and Menu buttons for at least 6 seconds untill the Apple logo appears.
  

If this does not work I would consider restoring. This means you will loose all your music,pictures, videos..ect. But from it sounds, you don't have anything on your iPod to loose.
update or restore iPod nano with the latest software: 
1 Go to www.apple.com/support/ipod and download the latest iPod Update. The update 
has the latest software for all models of iPod. 

2 Double-click the software installation file and follow the onscreen instructions to install 
the iPod update. 

3 Connect iPod nano to your computer and open iTunes. The iPod Updater application 
opens. 
If you’re using a Windows PC and the iPod Updater application doesn’t open 
automatically, you can find the updater by choosing Start > All Programs > iPod. 

4 Follow the onscreen instructions to update or restore iPod software. 
If you use the iPod Updater application and it doesn’t recognize that iPod nano is 
connected to your computer, reset iPod nano (see page 45). 
If you want to restore iPod software and you don’t have an Internet connection, you 
can use the iPod Updater application that was installed on your computer when you 
installed the software from the iPod CD. 

The easiest solution would be to plug in your ipod and click on your ipod in your itunes library. By doing so you should be on your contents tab. Click on the settings tab and then click on restore. This should add restore all your defaults on your ipod. Before you do all this; make sure you back up your podcast if you don't currently have them in your itunes library. If this was helpful to you in anyway please leave a comment and a good rate. Thank you!