Lots of good tips here. I will add (unless it was mentioned and I missed it) that skate parks are great training grounds for kids learning to ride. I would take my 2 - 3 year old son early in the morning before most anyone showed up and he had all the ramps and bowls and smooth concrete to cruise around on with his Strider balance bike. Obviously this is only helpful if you've got a park somewhat nearby. If so, I highly recommend it - it's an exciting place for a young kid and seemed to motivate my son to learn to ride and eventually show off around his peers when he graduated to pedal bikes and skateboards.