If you can learn the difference between needs, wants and extravagances, you’ll be ahead of many people.

Newly married couples should make a list of things they need each month – rent, food, utilities, car, clothes, student loan repayment – and things they want such as eating out or going to the movies.

“Newlyweds need to develop a spending plan,” says Mark Stempel, a certified financial planner and principal at Mark Stempel & Associates in Tucson, Ariz. “They also need to start thinking about the future – most people in their 20s aren’t looking out to what’s going to happen when they’re in their 60s. The couple should think about meeting with a financial adviser because they probably won’t initiate the conversation on their own.”

If a couple’s combined take-home pay is $3,000 a month and if rent and other needs require $1,200 a month, they have $1,800 left each month for savings, including retirement funds and a bank account.

Take money to cover needs off the top each month and then set aside money for savings. The balance is what you’ve got for wants. Money not spent on wants each month can be spent on extravagances.

You almost certainly know friends who invert the process, spending first on wild things like a red sports car, fancy clothes or exotic vacations and end up scraping each month to pay the rent. It’s a good bet that these folks don’t save anything because they apparently believe money is worthless unless it’s spent. Such wild spenders are easily crushed by a bout of unemployment or unexpected expenses such as medical bills because they have no cash reserves. The bank or auto dealer soon repossesses the car and the big spenders’ fantasy life is shattered.

Money has become increasingly abstract with credit cards and electronic transfers zipping through distant computers. You can give spending some grit by establishing a direct link between your spending and your money. If it helps at first, tuck receipts into envelopes marked “rent,” “car” and “utilities” to nail down where your money goes. Or, set up electronic transfers from your checking account to cover as many monthly expenses as possible and keep a wary eye on your bank statement.

Until you get the hang of money, consider stuffing a set amount of cash into an envelope each month marked “wants.” Use this for entertainment. If you’ve got $10 at the end of the month, you’ll have to skip eating out or going to the movies until pay day.

Remember: The program to develop fiscal discipline won’t work if you tap long-term funds such as savings on the sly to meet immediate needs or wants.

Setting priorities for your spending will help you manage your money. It seems like a no-brainer, but many young couples simply spend until the money runs out each month and therefore have little idea where the cash went.

The machinery to track your money and establish good spending habits may clank at first, but once you learn disciplined spending, all you’ll need is numbers on a spreadsheet to stay within budget. This will promote domestic tranquility by helping you better understand your spouse’s financial style.

Rule of thumb: If you haven’t got it, don’t spend it. If you can organize your personal finances around that basic truth, you’ll be ahead of millions of people who run up huge credit card debt and add unnecessary stress to their marriage.

Many brokerage firms have Web sites offering financial planning tips, including T. Rowe Price (TROW), Merrill Lynch (MER), Goldman Sachs (GS) and Morgan Stanley (MS). Major banks also offer solid information, including JPMorgan Chase (JPM), Bank of America (BAC), Citigroup (C) and Wells Fargo (WFC).