There are many many very good horse sites, most of which you probably know about. So I've tried to limit the selection here to my favorites and sites I think are important, but may be a little off the beaten path. Enjoy!

Horse Care Sites
The HPT Methods "Shoeless not Clueless!" At KC La Pierre's website you'll find plenty of info on his Barefoot Trim, hoof research, workshops and more. Go there!
Hoofcare & Lameness Articles, books and hoofcare resources.
Natural Hoofcare Natural Hoofcare Site authored by the famous Hoofcare Specialist, Jaime Jackson.
The Natural Horse Magazine Online version of The Natural Horse Magazine. Chock full of amazing articles, tips and ideas.

Horse Fun Sites
Cross Country International Now that you have someone to take care of your horse - Go on Vacation! I rode with them in Europe a few years ago - Tremendous!
The Ansur Saddle Talk about vacations! Give your horse a vacation with the treeless Ansursaddle. My horses use them exclusively!
Hidden Trails More horseback riding vacations!
Equitour Riding Holidays And more!