Child needs a mentor, inspiring him with confidence, and if the coach is attentive to him, then he would go to classes with pleasure. Not be amiss to inquire about the coach, ask friends, find information on the Internet, and then to go and meet with the coach personally.
Worth to attend the class, first without the child, merely to observe classes. Look at hunting whether children are engaged, whether they are full of enthusiasm, whether in the classroom benevolent atmosphere. During class there should not be unnecessary noise, the coach, who is able to channel the energy of children in the right direction will not allow the hubbub during the learning process, which is a sports activity.
Very important is the communication style of the coach if he humiliates students, allow swear words in relation to them, it is better to refuse the services of a mentor. 
A good specialist will be able to explain to their students their task without resorting to the Mat.
If the coach is attentive and moderately severe, it is worth it to look. The next step is to talk to the parents of the pupils of the trainer, as with mothers and with fathers. Mom will tell about the human qualities of a trainer, his character, and dad will appreciate as a professional.
Also good to talk with other students, ask whether they like the teacher, often praises them, asks about their health. It is very important how they talk about their mentor with shining eyes or with a bored look.
It is important to learn about the sporting achievements of the pupils you are interested in coach. Well, if the trainer has a large number of medals and sports awards, it will be an incentive for a child to repeat, and perhaps surpass his mentor. 
Now you need to talk with the coach personally, to ask questions, observe the gestures, facial expressions, form an opinion as candidly answering questions. If he was cold and annoyed when talking with parents, communication with children will be even less tactful.
When you have decided that the coach fits you need to bring the child on a trial lesson, all people are different and someone nice to talk to, and someone just can not stand. It's called human incompatibility. In this case, go to another coach, because with a man the child will never feel comfortable. If all went well, coach, you eventually found competent, it is necessary to trust in the future, regularly communicate with him, to be aware of their child's progress and help in achieving a common goal – to make the child healthy and strong man.
If the baby is in contact with his mentor, this can lead to remarkable results. A child's success in any occupation consists of 2-piece 20% the coach's work, knowledge, the right notes, the ability to motivate and 80% desire and effort of the child. When there is complete coincidence between teacher and student, there are outstanding personalities.
Pictured right: Yip man and his student Bruce Lee.