A diamond is forever
Simply put, money management is a set of rules and guidelines that keep your risk at a level at which you are comfortable with. It includes the rules you set for yourself every time you play telling you when to stop. Common sense should and must prevail throughout. Good money management starts with planning. Money management takes discipline and planning.
A few points on money management. Remember, that the house always has the edge and that it is always constant. If you think you can beat the house on a consistent basis, then my advice to you is quit before its too late.