A good quality rear-mounted child seat will carry your little ones in comfort and style. A quick-release model allows you to use the bike for other things without major hassle. As the child will be behind you and out of sight, they must be securely held into the seat with a harness. Always fit the child with a helmet that's designed specifically for this purpose - it will provide extra protection for the side and back of their head if the bike should fall sideways.