I don't have skills in archery but I am interested in introducing my children to archery via archery schools. I heard that archery is a good sport that will increase our focus power and our control power to emotion. I don't know when is exactly the right time to introduce my son to learn archery. Are there any good references about this?
If you live in the United States, you can check out the Junior Olympic Archery Development (JOAD) website, which is affiliated with USA Archery. For other countries, a visit to FITA (Federation Internationale de Tir a l'Arc) site might be a good starting point.
The JOAD site contains a FAQ that describes aspects of the program. The JOAD site itself notes:
JOAD is open to any youth archer aged 8 to 20 and is designed to grow with the youth archer. Introductory JOAD classes teach the fundamentals of proper shooting form; as the young archer develops, they will learn more advanced techniques.
From that description, it appears that children that are at least eight years old can start training. Of course, parents know their children best and may be able to start them off at a younger age.