sansa c150

How do I transfer audio books to audio book file on c150 from computer, make it easy not to good on computer, thanks for any help.

Have you ever heard of the Windows technique ‘drag & drop’?

The format that I have to use to download my books from the library is Overdrive Media.  I can’t seem to drag and drop from that format. 

Ah, true enough. You need to set your player to MTP mode, and use the Overdrive Media Console for these type of audio books.