If you are looking for a free (or very inexpensive) horse, one of the best places to look is rescue associations, or animal rescue groups which also deal with horses. These associations take on horses but have limited resources to take care of them in terms of space (stalls, pasture), money (food, bedding, etc.) and staff time (mucking out, general care). Consequently, they are normally looking for good homes to pass the horses onto, so that they can free up their scare resources to care for others. Therefore, they will usually pass the horses on for free, or for a nominal amount (to recover some of their direct costs).

In addition to getting a horse very cheaply, you are also doing a good deed by adopting the horse. In so doing, you free up the rescue association's resources, allowing them to take on other animals.

Before they give a horse to a new owner, the association will need assurances that the horse will be well taken care of. You will need to show them that you have the facilities (e.g. stall, pasture) to take care of the horse, or that you will be renting adequate facilities (e.g. at a professional horse boarding business). They will also want to be assured that you have the time, money and commitment to take care of the horse long term.

Before taking a horse from a rescue organization, you should learn as much about the horse and its history as you can. This will help you understand its capabilities (e.g. how much training it has), physical health, any behavioral issues, and any health concerns. In this regard, one should ask about the results of any veterinary examinations and the experiences of the staff when dealing with the horse while it was in their care.

In particular, one should ask why the horse has been taken into care. If it was simply because the owner could no longer keep it (e.g. due to financial difficulties) or lost interest in it (a common situation with horses purchased for young children), then the horse is probably sound. However, if the horse was rescued because it was neglected or abused, then it may have longer term physical or behavioral issues that you need to be aware of. Likewise, if the owner gave up the horse because it was sick or no longer suitable for riding.

One also needs to think carefully about the horse's current capabilities in terms of what you will use it for. Many rescue horses are old; if you only want the horse as a companion horse then this is not a problem but if you want to ride it regularly then an elderly horse is likely unsuitable. If the local rescue organizations don't have a horse that meets your requirements, the best solution is to wait. Leave them your contact details and your requirements, after assuring them that you will provide a good home for the right horse. You may need to wait a few months, but with so many horses being rescued for a variety of reasons, there is a very good chance that one which meets your requirements will become available.