The Equine Lameness Prevention Organization:

www.E-Hoofcare.com

The ELPO Farrier School :

www.elpofarrierschool.com

 Equine Digit Support Systems

www.NBHoofcare.com

A good site to find equine related resources  around the USA: 

http://www.horsenpony.com

The Farrier and Hoofcare resource center:

www.horseshoes.com