(MONEY Magazine) – Not so long ago, I was like most twentysomething baby boomers entering the work force. In the mid-1970s, I was just starting a job and thinking more about having enough cash for a couple of beers with my buddies than about preparing for retirement. The very idea of contributing 3% or 5% or, heaven forbid, 6% of my own hard-earned dollars to something known around the office as a retirement thrift account was anathema. "Retirement" and "thrift" were not in my vocabulary. There were apartments to pay for, cars to buy, trips to take and, of course, cold ones to drink.

Then in 1978, two years into my career as a writer and an editor for Time Inc., something clicked. The company had this deal where they'd put some dough into an account in their employees' names, and I was now eligible to participate. All I had to do was say yes and agree to deposit a small percentage of my pay into the pot, whose earnings would then grow tax-free. Now, I may have been a naive twentysomething, but I knew a good deal when I saw one. So I swallowed hard (for once, not Moosehead) and signed up. To this day, enlisting in Time Inc.'s savings plan--it wasn't even called 401(k) back then--is the single smartest money move I have ever made.

That humble account, begun with deposits of $57 a paycheck, has grown well into six-figure territory, thanks to the unerring steadiness of the contributions, to the company's matching deposits, to my ability to leave the darned money untouched and, mostly, to my selection of stocks as investment vehicle of choice. (Of course, a 14-year bull market hasn't hurt, either.) And while the account is nowhere near $1 million just yet, I feel sure that someday, like a financial Little-Engine-That-Could, it will pull me over the million-dollar mountain all by itself.

This month, in an unprecedented special report, we devote 26 pages to the care and feeding of your 401(k)--arguably today's most-talked-about investment product. No wonder: For an estimated 40 million or more Americans, 401(k)s or similar employee-guided salary-reduction plans like 403(b)s are almost certain to be the keystone of a financially secure retirement. As project editor Eric Schurenberg and his team of 20 reporters, writers and editors document, with proper tending your 401(k) has the potential to make you a millionaire.

But please note the key words in the preceding sentence: "proper tending" and "potential." Editor Schurenberg, who is also the author of 401(k): Take Charge of Your Future (Warner Books, $9.99), points out: "You don't have to be a genius to manage a 401(k) wisely, but you have to know what you're doing."

Alarmingly, quite a few people don't. Paul Yakoboski, a research associate at the Employee Benefit Research Institute in Washington, D.C., recently found that fully three out of 10 participants in 401(k) plans didn't even know whether their employers matched their contributions, and a nearly equal percentage (28%) had no idea how much they were contributing themselves.

Then there's the matter of how plan participants deploy the money they set aside. The answer: much too conservatively. According to a 1995 survey by benefits consultants Hewitt Associates, so-called stable value funds constituted an outsize 30% of employees' balances in plans offering such choices, and when low-yielding money-market funds were available, they grabbed a whopping 25% of assets. Stick with such sleepy allocations and, trust me, you can kiss that $1 million dream good-bye.

Seeing figures like those convinced us that the time was right for an extended package of articles on 401(k)s. What also persuaded us was the response to a newsletter we produce in association with Hewitt. In the three short years since its launch in mid-1993, Managing Your Future, a newsletter distributed to 401(k) plan participants through employee-benefits offices, has grown from 80,000 readers at 33 companies to more than 1 million at 305 large and small corporations--a 132% annualized growth rate that, sorry to say, even the best-run 401(k) account can't hope to match. Says Schurenberg, who edits the letter along with MONEY senior writer Penelope Wang, author of this month's lead story: "People are beginning to realize that the decisions they make regarding these plans really do matter. Working to get an 8% return rather than settling for 6% will mean a difference of as much as $1.7 million over the course of a 40-year career."

The bottom line: If you're already taking part in your company's plan, turn to page 94 and start getting smarter. If you're among the roughly 20% of eligible employees who have yet to sign up, take my advice and get going--now. Believe me, it will be the best money move you've ever made.

TYLER MATHISEN, Executive Editor