If you're like a lot of workers you won't have a defined benefit pension coming to you in retirement, and living on Social Security alone means you'll be cutting it pretty close to the bone.

So, unless you're angling to live like Mother Theresa minus the selflessness and international acclaim, you should take advantage of your 401(k), which offers you free money, tax breaks and a very convenient way to build your nest egg.

Any contributions you make will reduce your taxable income for the year and will grow tax-deferred until retirement. Plus, many employers will match a portion of your savings. And that extra dollop of money is tax-free to you.

The sooner you start, the better, since you won't have to save nearly as much of your salary to reach your goals if you start young than if you start in your 40s or 50s. (Not that all is lost if you get started late, it just takes a lot more discipline, as Walter Updegrave explains.)

Remedy:

Call your benefits office to find out how to sign up for your 401(k).

The task may soon be made easier for employees as more companies are adding an auto enrollment feature. Here's how it works: as soon as you are eligible to participate in the company's 401(k), a small percentage of your pay is automatically deducted and put in a 401(k) account. You are free, however, to change your contribution level and investments.