Selma Jones and her only child, Roger, aren’t crazy about each other, but they share a common desire – obtaining a higher living standard.

Roger’s 35 and makes $60,000 a year working for a landscaping company. Roger owns a large home that’s feeling pretty empty now that his girlfriend Thelma’s left. Roger hates to cook, clean, and do laundry. He spends lots of money eating out and having his place cleaned and his shirts pressed.

The $787 billion stimulus bill that President Barack Obama signed into law in February 2009 includes an $8,000 first-time home buyer tax credit. This is an expansion of a 2008 incentive that was essentially an interest-free loan.

Since 2010 everyone, regardless of income, is eligible to convert qualified retirement savings into a ROTH IRA. Doing so will require paying taxes on the amount converted; i.e., the amount taken out of the regular IRA and put into a ROTH IRA. We will see below that the value of the conversion can depend on where you live but also, even more significantly, when you intend to take Social Security.

John and Betty are very lucky. They are 30 years old; they just got married; and they have reliable jobs in today’s economy--earning $50,000 each. The couple has a 3 year-old and a 1 year-old. They plan to send their children to moderately expensive colleges and to retire at 65. They have a $12,500 in savings, plus $70,000 set aside for a down payment on a house.

For years the Social Security Administration urged retirees to take Social Security as soon as possible, even though doing so meant permanently receiving lower benefits. Here’s what they’ve said: “From an actuarial perspective, it doesn’t matter when you start collecting. But you may die early and regret (hopefully, in heaven) having waited, so don’t take the chance of dying before collecting. Take your benefits early.”

This advice and logic was as bad as it got. As far as we know no one has any regrets in heaven or needs any money.

Huck and Molly Finn from Hannibal, Missouri are both 30, earn $50K each, have a modest home, plan for one child in 2010, target to retire at 65, and expect to earn 3% real (after inflation) on their investments.

Their employers offer regular and Roth 401(k) retirement plans, but no match. Both plans can save taxes. Contributions to regular 401(k)s or IRAs are tax deductible, but withdrawals are taxable. Contributions to Roths aren’t deductible, but withdrawals are tax free.

Roth and regular retirement accounts provide significant opportunities for saving taxes over your lifetime. But deciding how much to invest in each and which to withdrawal first is tricky without the right software.