When you contribute to a traditional IRA, you can deduct that money from your taxable income that year. When you contribute to a Roth IRA, you don't get the immediate tax benefit -- but you withdraw your money tax-free in retirement. It's also possible to convert from a traditional to a Roth, but you have to pay taxes to do so. A reader named Ron wants to know how that works, and when he'd have to pay the taxes. DailyFinance's Laura Rowley explains.