Kids physically develop at slightly different rates. There are, however, milestones to watch for at certain ages. Keeping track of your child's progress in physical coordination at different ages can help reveal potential issues.
Great idea from another: "Mother & Child Mini Interview. Would be cute to do every year on your child's birthday. Put it in a binder with a letter to your dear one each year. Give them the binder when they are all grown up. This is soo sweet!