Make space for the horse to stay in your home, preferably a small stall in the corner of the barn. If you do not have ample space in your home for a horse you should just let go of the idea, as you will be causing a lot of problems for yourself and the horse.
Guide your horse to its place and tie it to a strong post. The first step in training a horse is to gain its trust, before you actually teach it anything. Easiest way to go about this is to bring it fresh food daily and stand there watching it eat. Also bring fresh water to the horse yourself, and do not let anyone else near it yet.
After a week or two, get close with it and pat its back. Place your hand around the neck region and stroke it gently, all animals love that. You should be able to see feelings of trust or likeness developing in its eyes for you.
After about 2 weeks time untie the rope and take it for a walk in the barn. Do not let it cross you, always make it follow you. You will have to work really hard on the walking phase if it is a wild horse. Coin a few terms such as ‘Start’ and ‘Stop’ and make your horse act on them. It may cause problems early on, but the key is to be patient and keep following the same routine till it starts obeying you.
Brush and clean your horse and mount the saddle on its back along with the hackamore and the bridle. Mount on the horse, keeping the reins straight. Reassure your horse with verbal commands and make it walk. Follow the same routine that you did for walking and it will start obeying your commands soon enough.