Bay Mountain Martial Arts
785 M & N Oak Grove Rd, Concord, CA 94518
My 11-yr old son has been attending for over 3 years and is working toward his brown belt; my 8-yr old son started the Dragons program recently after finishing Tiny Tigers and is working toward a purple belt.
You can read about the instructors at their website to get a sense of how they teach-- what I want to share is how they interact with the kids: maintaining firm control and discipline with gentle patience and consistency (keeping it safe for everyone); using games, drills and repetition; and giving positive feedback when it is earned. The kids embrace it enthusiastically. They love their senseis and orbit them like planets around the sun. :)
Warning: be prepared for L-O-N-G belt tests...even for the little kids. It would be nice if they had a larger facility so parents could sit down, in the meantime, wear comfortable standing shoes.
If becoming a black belt is your goal, this is THE place...for kids AND adults.