September 6 is National 401(k) Day (see www.401kday.org for more information). It's a holiday that most of us haven't heard of. Even if your employer isn't planning any festivities to celebrate it, here's how you can observe the day yourself.

• If you haven't opened a 401(k) yet, do it today. It's a painless and easy way to save for your retirement. Fill out the paperwork once, and your contributions are made automatically. Your contributions reduce your level of taxable income. So you might have less to owe Uncle Sam next April 15.
• If your budget is tight, or if you're nervous about investing, start small. Chances are that you will not even miss a one- or two-percent contribution from every paycheck.
• Make sure you contribute enough to be eligible for any employer matches.
• Read all the explanatory material about your investment options carefully.
• If you are confused, consider one of the plan's pre-set portfolios based on risk level. Or pick and choose among all the options to devise your own mix.
• Never have something in your portfolio that you don't understand.
• Attend any enrollment meeting at your company and ask questions.
• Check with your financial professional if you are unsure of anything.

If you've done all of the above, you certainly can pat yourself on the back. But don't think that entitles you to take 401(k) Day off! Take a look at your progress.

• If you haven't looked at your allocations since you opened your 401(k), make sure they still match your goals and current circumstances.
• Rebalance every 12 to 18 months, or as directed by your financial professional. Often, you can do this through your plan provider's Web site with one mouse-click.
• Maximize your contributions and get the highest match from your employer, if one is available. Many people think they contribute the maximum amount of 10 percent to their 401(k) every year, but, on average, a typical 401(k) participant only contributes between 4 and 6 percent.
• If you receive a raise every year, you should consider contributing a portion of that raise into your 401(k) before you get used to having—and spending—it!