Thank you to Mordak and Ian_Robinson. After reading their posts, I decided to give it another shot at installing my HP Photosmart c5140 printer/copier/scanner. (Using PC-BSD 9.2 release amd64 -- and my printer is on wifi LAN at home)
See my post above -- in my previous install attempt, I tried to follow the PC-BSD handbook instructions
and was only able to find a compatible printer driver but not able to set up scanning.
This time I used the HPLIP Device Manager that I had installed when I installed the OS (like what Mordak and Ian_Robinson suggested).
First, I chose "setup device".
Then I selected "Network/Ethernet/Wireless network" under Device Discovery popup -- and clicked on the "show advanced options" -- then clicked the check box "Manual Discovery" and entered the IP address for my printer. (If I didn't give it the IP address, it would not find the device on its own).
When I clicked "Next", it found my device accurately -- then I just had to browse for the correct PPD file -- for my device it was "hp-photosmart-c5100_series-hpijs.pp.gz". Then click "Add printer".
Not only am I able to fully use the printer over the network -- but now I am also able to make copies and scan pictures over the network as well -- again, using the HP Device Manager.
When scanning, it will use the XSane application and save the picture as a .pnm file.
As a tip, I could convert the .pnm file to a .jpg one using the following terminal command:
convert foobar.pnm foobar.jpg
Thanks again to those who posted above.