Learning how to export a PDF from GIMP will help you to export a single page or multiple pages of PDF from your artwork.

To print a large image or poster on multiple pages, split it into different parts. You can use MS Paint, PosterRazor or The Rasterbator.

In such cases, you might want to convert that physical book into a PDF or eBook that you can then read on the eBook apps on your iPhone or Android. There are several ways of doing so.