I highly recommend any classes taught by Ruth Haller, my and my eleven-year-old daughter's tae kwon do instructor for several years. Ms. Haller is a black belt, the mother of several children, and an experienced and gifted teacher of children through adults. She relates to children very well, including very young children like your son. She teaches classes in a variety of locations in the Portland metropolitan area:
*Village Home Education Resource Center (www.villagehome.org)
on T/W/Th 11-12:15 at 5150 SW Watson in Beaverton (for homeschooling families)
*Garden Home Recreation Center on Tuesdays, 5-6pm
*PCC-Sylvania campus (16yrs & up) on M/W 3-4:20
*Bushido dojo on Cornelius Pass Rd (across from Kohl's) on Thursdays, 1:15-2:30.
If one of her classes doesn't work for you, try to find a school that teaches traditional tae kwon do. Many of the schools are more money-making businesses than good schools. But a traditional school teaches not just tae kwon do as a sport, or as a business, but teaches the full mind-body-spirt of tae kwon do, including character building. Choi's Tae Kwon Do Academy in Beaverton is a traditional school, as is Choi's Martial Arts Academy on Halsey in Portland. Both of the Choi's academies have been in existence for many, many years, and have excellent reputations.
The meaning of tae kwon do is "foot-fist-way". Which means that the art of using one's legs as well as arms for self defense is taught, but also a way of life is taught (in a traditional school). Karate focuses on use of the arms, not the legs. Because the legs are longer than the arms, using the arms as well as legs for self-defense is more effective.
Hope this helps!
C.