Look at the industry standards that the company (and model) meets, then find out what is required to recieve these certifications. DOT standards are great on paper, but it is an honor system, the manufacturer test their owen products and decides whether of not they meet the requirement. Snell, on hte other hand, not only tests manufacturer provided items, but they also buy off the rack to ensure that the product that reach the consumer are of the same quality as the products that were tested. On the down side, there are those who believe that Snell approved helmets allow your head to recieve excessive G loads. If you look to the European makes, you can find ECE helmets, which may well be the least controversial. Definitely, try the helmet on first, and make sure that it is a good snug fit. I see too many kids out there wearing loose helmets, and their parents don't seem to care. The best helmet on the planet can't do it's job after it gets knocked off (and I have seen it happen).