What is natural hoofcare, an excellent introduction
Barefoot for soundness, an excellent website, with lots of practical information on trimming
Pete Ramey’s site, one of the world most experienced trimmer, author of numerous books and videos
Farrier supplies in the UK, mail order tools for barefoot trimming
Metal free horse, no shoes, no bit, no problem!
bitlessbridle.co.uk, iron free equestrian centre in Wales (horses are barefoot and bitless). Also supplies herbal wormers for horses.
Making Natural Hoof Care Work for You by P. Ramey. A must read for would be barefoot trimmers, with lots of photos and plenty of practical advice.
Feet First: Barefoot Performance and Hoof Rehabilitation by Nic Barker and Sarah Braithwaite. Plenty of useful background information, particularly about nutrition, and some very good photos, but note that this is not a trimming manual.
The Barefoot Horse: An Introduction to Barefoot Hoof Care and Hoof Boots by Lucy Nicholas . Very useful section on boots
The Soul of a Horse: Life Lessons from the Herd by Joe Camp. New comer to horses discovers natural hoofcare.