I've learned through the internet and dvd's. There's lots of barefoot websites out there with lots of good articles in em.
Make sure to check out Pete Ramey's website. I ordered the dvd's he put together, "Under the Horse", it's a 10 disk set.
Look at as many hooves as you possibly can. Even if you don't trim the hooves, simply cleaning em out with a pick and looking at the hooves will help ya cus you'll get to see lots of different things.
And if you go the self-educated route, I'd say be prepared to spend a lot of your time learning and reading and watching and asking questions. I've probably watched my Under the Horse dvd's 5-6 times.
Also if you can get ahold of cadevar hooves to practice trimming on you'll learn quite a lot quickly.
But I wasn't able to get cadevar hooves nor was I able to look at a lot of different horses hooves. But I know it would of helped me learn quicker.
Here's some websites. And there's some mentions of a barefoot trim on the sites, but I would advise against trying to do a trim from reading about it. But I'm a visual type of person, and I needed to see it done. Barefoot for Soundness Pete Ramey hoof care heals founder in horse’s navicular disease farrier The Horse's Hoof, News for Barefoot Hoofcare The Horse's Hoof, News for Barefoot Hoofcare
Check youtube for some barefoot trimming stuff. But I still didn't have confidence to do it myself until I watched my dvd's from Pete Ramey. And I never had a trimmer help me in person. So I have learned through reading and watching and it can be done. Although it is never advised, and if you can get personal help you will learn so much faster.