A family money-management plan with any hope of success will have to include the kids -- which is easier said than done. You can teach your 4-year-old to close the front door, but you can't expect him to understand that you don't want to pay for air-conditioning the whole neighborhood. A teenager, on the other hand, should understand that and more.

Lessons in financial responsibility must take into account a child's age and level of maturity, but there are general guidelines you can follow.

Adapted from Kiplinger's Practical Guide to Your Money, by the Editors of Kiplinger's Personal Finance magazine (Kaplan Publishing. Copyright 2005 The Kiplinger Washington Editors, Inc.) Available wherever books are sold or direct at kiplinger.com/store/books.