When I was his age they used to run them in schools - practice riding round traffic cones for an hour a week then do a test to show you knew hand signals etc. I was actually going to pay for a course but when I rang up the lady told me the council were running free courses in the school holidays, so I booked one of those. You could ask your local authority what they offer for road safety training, or get together with some other mums to book a course for your kids.