Parelli Natural horsemanship is the most popular natural horsemanship program in the world.  I myself am a parelli student through the home study packs, and a member of the parelli savvy club.  I highly recommend starting the Parelli Program if you want to have a good partnership with your horse, your horse will thank you for it!  The packs are available on ebay for around £90 each, there is a level 1/2 pack, level 3 and level 4.  Parelli teaches "The Seven Games" which are used as a foundation to build up your horses trust and respect.  The aim is to have a horse you can get to move forwards, stop, go sideways, go backwards with less than 4oz of pressure. I wish I had started Parelli years ago, it would have saved me from being kicked, bitten and run off with.

Parelli Myths

Of course there are people who say parelli is rubbish, but they just havent tried it and are happy to live in ingnorance.  I have read things saying parelli has cruel methods and you have to hit your horse with the carrot stick!  This is NOT true.  You can use the carrot stick to block your horse if he is about to hurt you or push into you, but that consists of waving it about, if your horse runs into the stick thats his fault and he won't do it next time, If I hit my horses with the carrot stick they wouldn't let me near them, instead they come over to me and are quite happy for me to swing the stick all round them.  You also use the stick to drive the horse away from you, this consists of rythmic pressure, first tapping the air and slowly getting close the the part of the horse that you want to move.  If that part of the horse isn't moving you tap the horse gently, adding more pressure every few seconds, until the horse moves away.  The horse has every chance to move away from the tapping, even if he doesn't the tapping is not hitting, it won't hurt him, just mildly irritate him at the most.  The aim is to move your horse without the stick touching him, which will happen very quickly,  The stick is meant as an extension of you, to make you have a "longer body" so you can reach your horse everywhere, it is not a whip, also is would be very hard to actually hit your horse with it, it is hard enough to tap with it!  A horse would kick another horse to move him, firm tapping is nothing in comparison.  It amazes me that people are shocked if someone taps their horse with a carrot stick, yet they are quite happy to kick,slap and whip hit, and yank their horse aorund by the mouth. 
Pat Parelli has received the Humane Horseman of the Year Award presented by the Humane Society of the United States (HSUS).  He wouldn't have got this if he hit horses with sticks. 

http://www.parelli.com