There are many horse training 101 manuals available for the riding and driving horse. This here has been used by very experienced drivers mostly breaking and training draft horses for the every-day use on a farm.
The horse should be well over two years old and have a quiet disposition.Try to teach him first to give hooves and to walk on a lead rope.He should be alright being handled and used to be tied up. But do not leave him out of sight while being tied up.
Start to put on a head collar with a breaking bit. Leave him for some time (max. 1-2 hours) in a loose box to get him used to the bit.
Lead him about and put some harness parts on. He needs to learn to stand still, while being harnessed up. Again, by moving him around, he will get used to the harness.
Your trustworthy and experienced helper's task is to hold a long rope tied to the bit. He will walk beside the horse in shoulder - line, but keeping a distance. The horse needs to learn to be driven, not to be led.
You should use as few, short commands as possible and his name. He needs to master those commands well, so you should gradually teach him to turn, to stop, to start and stop and to back up.
Try to practice these lessons daily for about 45 minutes.
Step 2 of the horse training 101
He needs to get used to water (puddles, ford, and stream) on the way and plastic bags, sacks or similar things, which are lying around, crackling and flowing in the wind. He should walk over them without becoming scared.
Pass tractors, cars, Lorries, motorbikes, etc. first when parked, then with engine switched on and later when they are driven and pass by beside the horse. Try to practice this in your yard or other, safe premises away from public roads and traffic.
If you intend to work the horse in different disciplines (carriage, farm work,...), wean him to wear different harness types, e.g. cart gear, plough gear, trace harness,...) All harness should be in good working order, but avoid using the best harness.
Put traces on and teach him to step over the chains and step back. The horse will learn to have them around his legs and get used to them.
For the first time pulling, attach a log (can be a railway sleeper) and have your helper beside the horse holding the long rope. Such a lesson should not be longer than 20 -30 minutes and ideally being repeated daily until everything is perfect.
In case the horse takes off because he is frightened, let go the off-side rein and the helper will pull the horse to the near side. A big mistake is to let the horse go straight on, as he will become faster and faster and more and more frightened.
If he stopped, untangle everything and start as if nothing has happened. Continue at once and do not cease now the lesson!
The next step in this horse training 101 is to put him together with an older, experienced, quiet horse. Put them together with single-slided chain harrows. Your helper still needs to be beside him holding the long rope. The other horse will pull him along and helps to pull him back to a sensible pace.
If there is no other horse available you have got to hold him at all time to a steady pace.
Especially turnings are difficult for a novice horse, because he will have to go faster or slower. So take your time practicing turnings.
Make him backing into shafts: place two pieces of wood in an angle onto a gate (higher ends towards gate, other ends lowered down on ground) and let him back up between these two "shafts".
If he is doing things right do not forget to praise him. You need patience, time and an even temper.He will never forget what he learns in this stage.