If you are looking at potential owners through an adoption application, and checking vet references, doing a home visit as to where the animal is going, charging an adoption fee that might cover your expenses on it, and making them sign an adoption contract, that stated the animal would not be sold etc and would come back to you if something happened where they could not care for it anymore, then you would consider it an adoption - if you are giving them complete ownership of the animal regardless of what they do with it later on, then you're just selling horses. Research Equine rescues, and talk to the owners/volunteers of these rescues and you'll learn a lot from them. Also, remember, you're not going to make money at rescue, the costs going out for vetting is way higher than what you're going to get back as an adoption fee. If you're a 501(c) THEN, you can ask for donations to help fund your rescue etc, but otherwise, you're basically on your own. The decision to become a rescue, and then building your reputation as a REPUTABLE rescue that vets their animals, etc, etc, etc is very time consuming and one "goof up" can really hurt your reputation in the rescue world, those of us in rescue are as cynical of humans as they come, but then again, we are the ones out there in the trenches seeing the abuse and neglect first hand. Best of luck to you, oh, and you might find some good rescues in your area by going to www.petfinder.com
and clicking on shelters and rescues - that will give you a starting point .....also, look deeply into your heart and ask yourself this....can I make a difference in this animals life, and am I doing it for money or for the animal....when you come to that answer, you'll know what direction you need to take.