Learn about credit
Tout the virtues of paying in full and on time. Some college students believe that carrying debt is a good way for them to build a credit history. You should explain that showing you can handle credit responsibly is a good way to build credit history. The best way to do that with your credit card is to pay off all that you owe -- not just the minimum -- on time.
Show the connection between debt and work. If your kids don't get just how expensive high-interest debt can be, show them in dollars-and-cents. (Two calculators that can help: CNN/Money's debt reduction planner and CreditCardNation.com's debt zapper.)
And for good measure, show them how much it will cost them in workable hours, Manning suggested. That is, convert the amount that they'll pay with interest into time worked based on their hourly wage. (If the student doesn't have a job, assume minimum wage.)
For example, paying just the minimum owed every month on a $1,000 balance at 19.9 percent interest will cost a total of $2,056 or nearly 206 hours of work, assuming the student makes $10 an hour after tax.
Show them the future. Manning will release a calculator this summer on CreditCardNation.com that will help college kids get a realistic sense of their post-graduation budget based on the debts they're incurring (or thinking of incurring) while in school.
Using real salary and tax data from recent graduates who majored in a user's subject, the calculator asks students to plug in their expected loans and credit card debt (or to use national averages) to see just how much they'll have left over for living expenses.