We have downloadable templates in PDF format for all trim sizes that you can use for formatting your front and back covers. You will find links to download the PDF files in the formatting section on the cover page of "Create a Print Book flow". Instructions on how to use the templates can be found within the downloadable template. More information on cover templates can be found in our Formatting Guide.
For interior files, we have standardized settings that you can apply to your existing document that will ensure proper PDF creation. See our Book Interior Quick Guide Checklist.