I train horses in my spare time.
I do as well! It is true that horses have been trained to be manageable by humans for everyday care as well as for equestrian activities.
Do you make a lot of money training horses?
It depends on where you live. Horses over the years have trained for warfare, farm work, sport and transport.
I see, and do you need any special education to become a horse trainer?
Well when I became a hand I noticed how much controversy their was over various methods of horse training. But really you just needs to be hands on.
What are some controversial methods of horse training? I have heard about trainers giving their horses drugs.
Well some techniques are considered cruel, other methods are considered gentler. I prefer to give them rewards for good behavior.
Do you start training your horses when they are young?
information about various schools and techniques of horse training.
Goals.
The range of training techniques and training goals is large, but basic animal training concepts apply to all forms of horse training. The initial goal of most types of training is to create a horse that is safe for humans to handle (under most circumstances) and able to perform a useful task for the benefit of humans 
A few specific considerations and some basic knowledge of horse behavior helps a horse trainer be effective no matter what school or discipline is
Horse training
Horse training refers to a variety of practices that teach horses to perform certain behaviors when commanded to do so by humans. Horses are trained to be manageable by humans for everyday care as well as for equestrian activities from horse racing to therapeutic horseback riding for people with disabilities.
Historically, horses were trained for warfare, farm work, sport and transport. Today, most horse training is geared toward making horses useful for a variety of recreational and sporting equestrian pursuits. Horses are also trained for specialized jobs from