WOW nmb…I thought no one would ask 
Actually, thoughout the thread I have put in many disclaimers and there was a couple of inferences of where I get my info. But, you have asked a very valid question, so for the record here are my some of my sources:
I am a farrier’s wife, so we have lots of “feet” discussions in our house. Hubby specializes in theraputic cases and uses his own technique which parallels Ovnicek’s Natural Balance method in many ways.
I have been interested in “natural” trim methods for about 3 years and have tried to find every source I could to research the technique.
I am on several other boards that discuss nothing but feet and trimming (generally barefoot, but it is the underlying trim that counts…barefoot or shod).
Here are a list of some of the books that I have read:
Butler’s Horseshoeing Principles
Adam’s Lameness in Horses
A Lifetime of Soundness, Strasser
Shoeing in Your Right Mind, Butler
Color Atlas of the Horses Foot, Pollitt
Equine Locomotion, Back and Clayton
Preventing Laminitis in Horses, Mansmann and King
Founder Prevention and Cure the Natrual Way, Jackson
New Hope for Soundness, Ovnicek
The Natural Horse: Foundations for Natural Horsemanship, Jackson
Horse Owners Guide to Natural Hoof Care, Jackson
Understanding the Equine Foot, Jurga
Magazines we subscribe to:
Hoof Care and Lameness
The American Farrier’s Journal
The Anvil
The Horse
and numerous other general horsey mags
Online articles at these websites:
www.hopeforsoundness.com
www.barefoothorse.com
www.naturalhorsetrim.com
www.horseshoes.com
www.americanfarriers.org
www.hoofcare.com
http://cvm.msu.edu/RESEARCH/efl/publications.htm (Dr. Robert Bowker’s research)
www.thehorse.com
www.aht.org.uk
www.hoofproject.com
www.laminitis.org
And I have these videos:
Horse Foot Studies Video, Pollitt
EDSS Instruction Video, Ovnicek
Strasser Optimum Hoof Form - The Basic Trim
In the last year there have been some great new stuff released and I expect that I will be adding to this list over the summer.
As for my personal experience with trimming:
zippo, nada, nilch…I hold the horses while hubby trims. Like any owner, I only observe and ask questions. I don’t claim to have any more understanding than any other horseowner. And, I don’t claim to understand much in the way of actually trimming, other than the basics that most horseowners understand. I haven’t rasped a foot in over 20 years, and never took nippers or knife to one. I have little knowledge of applying shoes, but more of forge work (hubby was a blacksmith before becoming a farrier). However, I do know in theory the proper application of a shoe and understand basic use of therapeutic devices like wedges, pads, and frog/sole support. I only know from my husband’s success that correctly balanced and aligned feet make for sound, happy, healthy horses. 
Hope you aren’t to disappointed…maybe you don’t approve. That’s ok too. I am only trying to share my knowledge and experiences. Not trying to force anyone into believing what I do. I am certainly no “expert” and find discussions like this to be exercises in knowledge for everyone. I certainly have learned from it! Just hoping that I can get others to research and try and gain an understanding of how the hoof functions and therefore how it should be trimmed to attain optimal form to accommodate that function.
So, do you disapprove? 
Forgot to add…we also have a shelf full of bones and a bunch of feet in our freezer. I think that disections are one of the best ways to understand what happens under different circumstances in the foot.
Proud member of the * Hoof Fetish Clique *
[This message was edited by slb on Mar. 06, 2003 at 05:28 PM.]