experienced horse person when deciding on a horse. Insist on a
trial period, and have a vet examine the horse.
Another source to adopt a horse is through the U.S. Bureau of Land Management. The round up wild horses and sell them for a small fee. But these horses are unridable without several years of training. If you want a wild Mustang, go for it, but most horse enthusiasts should pass on this one.
Many horses are put up for adoption simply because the owner, for whatever reason, doesn't want him anymore and just wants to see the horse go to a good home. But usually it's being given away because the owner tried to sell him and nobody wanted the horse.
Remember, when you aquire a horse, the horse's problems become your problems. Don't take a horse just because it's free.