When choosing a martial arts school, an important step, is to recognize that choosing a school is really choosing an instructor.
Be sure to visit the school and watch the instructor work with other children of the same age.
Every school is very different because every instructor is different.
Don't get confused by claims of black belt degrees, tournament wins or martial art styles.
The only style that matters is the teaching style of the instructor and how your child or you will respond to him or her.
Be sure to find out who specifically will be teaching the classes. Some schools have a qualified head instructor but use less qualified junior instructors to teach classes which doesn't serve the students to its fullest.