Wall Street is cluttered with commonplace financial advice. But if you want to get your career as an investor off to a smart start, sometimes you should consider ignoring those time-honored maxims. To help get you headed in the right direction, consider these three suggestions instead:

1. Investing isn't an either/or proposition.
For too many folks, investing is a zero-sum game. However, depending on your timeline and tolerance for risk, all of the market's major asset classes -- from the most dynamic growth stocks to more modest fixed-income vehicles -- can play roles in your portfolio. After all, spreading your bets around can help take the sting out of market downturns.

For example: Between March 2000 and December 2002, the Russell 1000 Growth benchmark -- an index that currently counts IBM (NYSE:IBM), Monsanto (NYSE:MON), Hewlett-Packard (NYSE:HPQ), and PepsiCo (NYSE:PEP) among its major holdings -- fell by some 24.8% on an annualized basis. Meanwhile, the Russell 1000 Value bogey -- which specializes in cheaper big boys such as Devon Energy (NYSE:DVN), AT&T (NYSE:T), and Pfizer (NYSE:PFE) -- shed just 1.7%.

Moral of the story: Don't go whole hog. Tilt in the direction of your investing temperament, but err on the side of a diversified portfolio. Speaking of which ...

2. Funds and stocks can live peacefully -- and profitably -- in the same portfolio.
I believe that a solid portfolio begins with top-rate mutual funds. And while you can always opt for an index tracker such as the SPDRs (SPY) exchange-traded fund, remember that, with index picks, you're destined to lose to the market each year by about the amount of your expenses. One solution is to mix index funds with actively managed keepers -- funds that allow you to invest outside your area of expertise and across the market's various cap ranges, with managers who have proven over time that they can deliver the goods.

Once your fund portfolio is in place, you'll be in good position to go about the business of researching individual stocks -- and, if they strike the right profile, investing in them as well.

3. Stay current.
From truisms like "buy low, sell high" to "let your winners run," investment wisdom is plentiful. Executing on those chestnuts is one challenge; staying abreast of the investing landscape is another. Time-tested advice is great in the abstract, after all, but you still have to put it to use in real time.

When it comes to doing that, a helping hand can be, well, helpful. That's particularly true for folks who are just starting out. At the beginning of an investing career, the market can look like an obstacle course, a daunting prospect that may prevent you from even getting started down the path to financial independence.

Not to worry: Smart investing is easier than you think. We launched Ready-Made Millionaire earlier this year in part to help new investors -- and those playing catch-up -- get up to speed fast. At the center of the service: a compact, real-money portfolio that tilts toward growth with a collection of world-class funds, cherry-picked individual stocks, and an ETF that we believe is poised to surpass the S&P 500. With just eight holdings in all, our mission is to beat the market over the next three to five years and beyond with little in the way of muss or fuss.

RMM is set to reopen to new members in the new year. If you'd like to learn more about our set-and-forget portfolio, just click here. A completely free copy of our "11-Minute Millionaire" special report is yours for the taking, too. Grab it now.

This article was originally published on June 11, 2007. It has been updated.

Shannon Zimmerman runs point on the Fool's Ready-Made Millionaire service. At the time of publication, he didn't own any of the securities mentioned above. The Fool owns shares of Pfizer. Pfizer and PepsiCo are Motley Fool Income Investor recommendations. Pfizer is also an Inside Value pick. You can check out the Fool's strict disclosure policy by clicking right here.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.