Children have to learn the value of money and how to wisely spend or save as soon as they learn how to count. If you do not introduce them to this, they may have problems later in life. There are generally 4 things you can do with your money. You can spend it, save, invest on something, or donate it to charity. Perhaps the most critical among the four is learning how to save. For that you can give your child a piggy or coin bank.
You should also let him handle his allowance. Start by giving him a weekly allowance, and then tell him that he can do whatever he wants with the money, but if he runs out before the week end then that would be his choice. Let him learn from his mistakes, but if you see that he really doesn’t get it, then that is the time that you have to intervene and talk to him.