How do you create a mixed media disc? I would like to include a slideshow/movie as well as include a .pdf of a photo book on the same disc?
Do you want the pdf available to view or just for copying from the disk to a computer for viewing.
To view a PDF you can do a Print ➙ PDF ➙ Save PDF to iPhoto which will create a jpg of each page of the pdf and save it to iPhoto. From there you can send the PDF jpegs to iDVD to make a slideshow of the pages. It's the same principle as used in this tutorial: 06 - Creating an iDVD Slideshow From an iPhoto Book.
If you don't have the Safe to iPhoto workflow in your HD/Library/PDF Services folder you can download it from Toad's Cellar.