The PDF Module allows for the upload of PDF files to the Library which can then be added to Layouts.
If the PDF file has already been uploaded to the Library use the Library Search tab to quickly and simply add to a Region.
Click on the PDF Widget on the toolbar, add / drag to the target Region. 
If you are using 1.8, select PDF from the Widget Toolbox to add to your Region Timeline.
Click on Add files to upload to the Library or click on View Library to select an uploaded file.
EZSignage uses pdfjs to display PDF's on the Player and in the Layout Designer.
Increase the duration to show a PDF page for longer.