Comedy shows such as Saturday Night Live work because, even in their warped way, the skits are believable. Flash back to last Saturday night. Shortly after the show's opening number comes one of those signature SNL faux commercials, this one featuring a fictional broker called Grayson-Moorehead. The pitch begins with an elder gentleman -- nattily dressed and comfortably surrounded by leather chairs and a roaring fireplace -- explaining the dedication of his firm's experienced team and traditional Wall Street investing approaches. Terms such as "dividend growth" and "return on equity" are bandied about. It's almost exactly like one of those brokerage come-ons you'll find every 15 minutes on CNBC. And that's when the hook lands.

With perfect comedic timing, the pitchman leans into the camera and whispers in an authoritative tone: "At Grayson-Moorehead, we do things a little differently." Indeed. Apparently, Grayson-Moorehead specializes in investing in important companies doing important things. No, we're not talking about General Electric (NYSE:GE) or Microsoft (NASDAQ:MSFT). More like the Goliath Extra-Large Cell Phone Company (Ticker: THUD) and now-bankrupt Enron. These and other firms were said to be part of the firm's signature Tax-Advantaged Select Growth Fund (Ticker: OOPS), the pitchman says as he fixes a drink that most assuredly includes finely aged bourbon. But there's bad news here, too: $100,000 invested would have been lost within five years and left the client with a whopping $840,000 tax bill. So much for "tax-advantaged," eh?

The so-called ad ends with a tribune to former President Theodore Roosevelt, who urged Americans to dare mighty deeds at the risk of ultimate failure. The pitchman compares Grayson-Moorehead's clients to those who followed Roosevelt's creed, happily tasting defeat rather than sitting idle. No wonder the tagline for the faux firm says Grayson-Moorehead has been "losing its clients money with dignity and pride since 1926." I couldn't help but laugh out loud, because it all seemed too true to be an SNL skit.

Many professional managers aren't worth the money
We've talked about it here at for years and years, but many professional money managers -- that is, those who invest billions in stocks on behalf of others -- tend to lose to the market's averages over time. This is true even though some actively managed funds have done very well against the benchmark S&P 500 over the last five years. (Still, it's important to remember that there are only 350 domestic-stock funds that beat the S&P over the trailing five years. Fund researcher Morningstar tracks more than 14,000 funds from of every conceivable size and style.)

But I'm not here to take potshots at mutual funds, since there are plenty of excellent funds out there offering market-beating returns. (Just ask Motley Fool Champion Funds chief Shannon Zimmerman; he'll tell you.) Instead, I'm here to poke at the soft underbelly of full-service brokers who, in the white shoe Wall Street tradition, look a little too much like Grayson-Moorehead without intending to. These are folks who take over your portfolio and invest it in what they think will be best for you over time. They charge huge fees to do this -- often portfolio-destroying fees. At least, that's the case with at least one person I know. His full-service broker has charged more than 2% per year for the privilege of losing massively to the market's overall return.

It's OK to let go
Knowing all this, it's very tempting for me to just tell you to fire your broker. Go do it yourself. We've got a Fool's School to help you get started without spending a dime. We've also reviewed many of the top discount brokers to help you select the right mix of cheapskate fees and needed services. And our newsletters offer a selection of stock and funds that are walloping the market. Yet I'm also a realist. I know that if you've been using a full-service broker for a number of years, you probably just want someone to manage your money. OK, fine. I get it. But...

...You wouldn't buy a car without knowing the invoice price, would you?
Of course not. You wouldn't buy anything without knowing first exactly what you were getting. And you'd probably want to know the best price before you bought. So why is it that so many of us simply hand over our finances without even remedial knowledge of investing or personal finance?

Ask yourself: Would you trust your broker with your life? No? Well, I've got news for you: If you're trusting him with your retirement accounts, then you're at least putting the quality of your life in his hands. Scared yet? Good.

Three things you can do that won't cost a thing
If you decide to go with a full-service firm you should get the best one you can afford, and a portfolio manager whose record for market-thrashing returns reaches back years. But even that's only the beginning. You're going to need to stay involved to be sure that your manager is doing right by you. If you're barely literate when it comes to financial matters that may sound like a tough job. It doesn't have to be. Here are three things to do right now with your full-service broker:

  1. Make your broker take you to lunch once a month, on him. Trust me, he can afford it. Even if all you do is go have coffee at Starbucks (NASDAQ:SBUX) with your local sales representative, take advantage. Bring your statement with you. Write out a list of questions you want answers to, and then keep a copy for yourself and provide a deadline for when you want answers. (By the way, the top of that list should be: "What are you charging me, how often, and what are my returns after expenses compared with the S&P 500?")
  2. Grade him. Remember getting report cards? I do. I loathed them. Not that I got bad grades; I just hated the suspense. Your broker will, too. Grade him each quarter on his performance versus the overall market and in generating cash to accomplish your goals. If you're losing to the market over the short term don't get mad, but do ask why. Does he have a plan to deliver outsized returns over the three- to five-year pull? Great. What is it?
  3. Get Foolish. As you check up on your broker you're bound to run into situations where you'll ask a question and get unintelligible drivel in response. Don't worry; that's what we're here for. You can post your notes to the Full Service Broker discussion board. Or you can Ask a Foolish Question. And if you really need help, there's our independent, fee-only TMF Money Advisor service that can help you do handle almost any conceivable financial need -- from creating a budget to finding the best mutual funds.

Leave the marble floors to Vegas and the sausage... somewhere else
The fireplace, fancy drink, wood paneling, and leather accoutrements of SNL's Grayson-Moorehead remind me of an old Peter Lynch maxim about companies worth investing in. According to Lynch, inexpensive and poorly located headquarters indicated management was more interested in growing the business than making themselves comfy. Remember that the next time you arrive at a fashionably arranged office for your broker. Where's that money going? Have they got marble floors? Great. So do Vegas casinos. But unlike those Sin City cathedrals, your broker is actually supposed to make you money.

Paying too much in investing fees can wreck your portfolio. But there are expensive full-service brokers out there who are worth every penny. Just make sure that, unlike Grayson-Moorehead, they aren't spending your money on the latest offering from Crocodile Dundee Smoked Dingo Sausage, Inc. (Ticker: YUCK). You can do better.

Fool contributor Tim Beyers looked it up on the Web; there really isn't a Grayson-Moorehead Securities. For good advice finding a full-service firm that will treat you the way you deserve, check out the Fool's Full Service Brokers discussion board. Tim didn't own shares in any of the companies mentioned in this story at the time of publication. To see what stocks are in his portfolio check out his Fool profile, which is here . The Motley Fool has a disclosure policy .