Did a search of this, found a nice solution, then when I downloaded an updated version of NOOBS it came with a much nicer PDF viewer built in along with all the Libre stuff.
This link suggested using the xpdf viewer and gives a command line example. This worked although the xpdf viewer is quite bare-bones. https://www.raspberrypi.org/forums/viewtopic.php?f=91&t=8005
I had another link that showed how to set up the double-click response for a particular file type, but I've lost the link. This other one talks a newbie similar to myself through how to bring up the GUI menu for doing the association (just right-click on the file and find the equivalent option to "Open With..."). https://www.raspberrypi.org/forums/viewtopic.php?f=91&t=98015
