I'm delighted that so many readers join me online for my regular chats. Unfortunately, I can't answer all the questions. So here are some questions from readers who recently joined me online, with my answers and responses from experts:

QMy company does not match my 401(k) contributions. What percentage of my salary should I save in my retirement fund? By the way, I am married and in my late twenties.

AFirst of all, good for you for thinking about saving for retirement at such a young age. And you get another pat on the back for wanting to contribute to your employer-sponsored plan even without a match.

According to a survey released earlier this year by CIGNA Retirement & Investment Services, fully one-third of "millennials" -- people born after 1979 and who are just entering the workforce -- fail to participate in their employer-sponsored 401(k) plans. This is more than twice the rate of nonparticipation of older baby boomers who plan to retire soon.

The CIGNA survey also found that young workers were 19 percent more likely than older boomers to label their 401(k)s "the benefit of yesterday."

If you are young, you have time on your side today. As Benjamin Franklin said: "Remember that time is money."

Dallas L. Salisbury, president and chief executive of the Employee Benefit Research Institute, recommends that this young person put at least 15 percent of his or her salary into the retirement plan and "do it consistently."

I am buying a small rental house for $20,000. It already has a reliable tenant in it. Because I do not own my own home and I did not have money saved for a down payment, it was easier to take out a personal unsecured loan instead of a mortgage. Can I refinance a personal loan?

Wow. A house for $20,000 and a good tenant. You should be dancing a jig. You need to check with the bank or credit union you borrowed the money from to see if you can refinance, advises Laura Armstrong, vice president of public affairs at the Mortgage Bankers Association.

How should I determine the amount of life insurance my wife and I would need to provide for our children if either one of us were to die?

Good question, and one for which many parents fail to get an answer. "For the working parent or parents, if you need both incomes, then you need to determine how many years of your income you want to try to replace," says Sheryl D. Garrett, founder of the Garrett Planning Network, a nationwide network of fee-only financial advisers. "I find that most people need at least 10 times their gross annual salary to cover expenses and to provide for the surviving family."

Garrett also says people often forget to get life insurance on the stay-at-home parent. "I recommend no less than $250,000 if they have minor children," she says. "The reason? The working spouse would need to pay to provide services that the stay-at-home parent would provide. The ages of the children would also help determine how much additional coverage a family might need above and beyond $250,000."

If you're unsure about how much life insurance you need, try the life insurance needs calculator created by the Life and Health Insurance Foundation for Education at www.life-line.org/life_how_ineeds.html.

The group's insurance calculator, like many others, uses a number of variables to help you determine the amount of life insurance to buy. You will be asked about your expenses, mortgage amount and savings and investments. The calculator is easy to use and a great starting point for figuring out how much insurance you might need.

What is the deal these days with getting married and "inheriting" your spouse's credit rating? Is it true that once you are married, a spouse with negative credit ratings could hurt a spouse with positive credit ratings?

The answer is true and false. Technically, most people don't "inherit" the bad credit rating of their honey simply by getting married. But it is true that your spouse's bad debts can become a problem for the family. For example, your spouse's poor credit could prevent the two of you from buying a home. However, if you keep your credit accounts separate and you don't become an authorized user on any of your spouse's credit accounts, then your good credit shouldn't be tarnished by the bad credit record of the spouse, said Evan Hendricks, author of "Credit Scores & Credit Reports: How the System Really Works, What You Can Do."

How long do I need to keep my 401(k) and Roth IRA statements?

You should permanently keep all of your year-end statements, suggests Cheryl A. Costa, a certified financial planner in Natick, Mass. "If you want to be conservative, you can keep the quarterly statements, but once you get to December you can just keep the year-end summary and then discard the previous quarterly statements," Costa says.

And remember, Costa adds, you should always read over your quarterly statements to check for accuracy.

Researcher Lorraine Denis-Cooper contributed to this column.

Michelle Singletary discusses personal finance Tuesdays on NPR's "Day to Day" program and online at www.npr.org. Readers can write to her at The Washington Post, 1150 15th St. NW, Washington, D.C. 20071 or send e-mail to singletarym@washpost.com. Comments and questions are welcome, but please note that they may be used in a future column, with the writer's name, unless a specific request to do otherwise is indicated.