I suggest you buy your son a chess primer first, and recommend Xu Jialiang's Introduction to Chess or Ram Raymond's Elementary Chess. The authors of these books have many years of experience as national elephant coaches, and the contents of the books are very practical.

Interest is the key. If your son is really interested in the national elephant after reading the primer, you can consider sending him to the Children's Palace, interest classes and other places to study the national elephant systematically. Your son has a lot of room for development after he is young.

At the same time, you can also consider buying some software about the national image. Nowadays, children are generally interested in computers, and you can also use software to guide them when learning the image of the country. The recommended softwares are Chess Master Edition 10 (this version has Chinese version) and Chess Master Edition (English version). These softwares all have their own phonetic teaching library, so that children can learn the basic knowledge of national image with software on the computer.

I hope my answer can help you _