How to fall in love with old-time music

-Wean your fledgeling tastes on authentic (whatever that means) grunge, punk, metalcore, anti-folk or any other kind of music that values a raw sound and a delivery that's got some blood and guts to it.
-Fall in love with Johnny Cash through his American Recordings. (Listening to Willie Nelson's Teatro album doesn't hurt either). Repudiate your belief that country is inherently crappy (that's probably just urbanite prejudice anyways).
-Watch O Brother Where Art Thou? Realize how much fun the music is.
(Later it will strike you as just a touch smooth and overproduced).
-Watch Ghost World. Share Enid's entrancement with 'Devil Got My Woman.'
-Listen to New Orleans Jazz, possibly the most joyful music ever made.
-Discover Lightnin' Hopkins, the gateway drug to old acoustic blues.
-Revel in the aching beauty of the Stanley Brothers. They put the blue in bluegrass.
-Listen to Skip James and the Carter Family, the lonesomest, spookiest, most gorgeous music you can imagine.
-Dig deeper and find the dirtiest, rawest music out there... Son House, Blind Willie Johnson, and Roscoe Holcomb. (Mix Charlie Patton and Robert Johnson in to taste).
-Enjoy.
-Share with others

Specific recommendations:
Lightnin' Hopkin's 'Best of' put together by Columbia actually is. Check out Mississippi John Hurt's Folkways recordings, while you're at it for a really genial, wonderful take on country blues.
I like the Stanley Brother's Columbia Sessions, but a lot of bluegrass fans prefer the Mercury recordings.
The Carter Family's Decca Sessions, though the Columbia ones are also good.
The definitive New Orleans Jazz band was King Oliver's Creole Band, especially during the years Louis Armstrong was playing second cornet. These recording are also criminally hard to get a hold of, unfortunately.
"The Legendary Son House, Father of the Folk Blues" has been re-labelled and re-packaged various ways. The original copyright holder should be Columbia, the recording made in the 40s.
Roscoe Holcomb has a couple of recordings on the Smithsonian Folkways Record label. Start with the first.
Blind Willie Johnson and Robert Johnson only recorded enough music to fit on one album, so in whatever form and with whatever title you find it it will probably be complete.
Ditto for Skip James when it came to his original recordings in the '20s and 30s. Avoid his '60s folk revival recordings, at least for the first taste.