Okay, I think I finally got it. Here's what I did:
1.) Open the Footprint Libraries Wizard
2.) Select 'Files on my computer' and find the .mod file that is accepted (clearly not fully understanding this...)
3.) Click 'Next' on the 'Review and confirm changes to the libraries' dialog
4.) Click 'Finish' in the 'Where do you wish the new libraries to be added' dialog
I can now pull my own custom footprints from the PCBnew editor.
If someone can clarify, it would be greatly appreciated. When I tried to use the wizard to create a custom library that wasn't named 'test', it would accept my '.mod' files as acceptable/clickable...