I am on a Mac. OS X Yosemite.
I have gotten the file to convert to CMYK when creating the pdf. I use File/Print/Save as Adobe PDF and choose PDF/X-1a:2001. (This was the PDF format that Sheridan suggested) It just has strange percentages for CMYK. The most I ever got the K was 96%. That was when I used a Grayscale Theme in Word. I think there has to be a setting to tell Acrobat to preserve black when creating the pdf. I just can't find it.
I have published other books with Sheridan in the past, and they provided a pdf converter. Now they suggest laying out the book in In Design. I do not want to have to completely lay out the book again. May have to find another place to print/bind the book.