By Anne Fisher, contributor
FORTUNE — Dear Annie: I was interested in your column about how to get back into the workforce after a long time-out to raise kids. I’ve been a full-time mom for four years and would like to pick up my career where it left off, or at least try to get my foot in the door somewhere. I’ve been wondering whether it would be possible to work from home for now, since my children are still pretty small, but I keep hearing that most work-at-home jobs you see advertised are frauds. How can I avoid getting stung? Most of my work experience is in customer service. Can I find a legitimate at-home job in this field? — Mary Lou
Dear Mary Lou: Thanks largely to the Internet, the number of people working from home in the U.S. has skyrocketed to over 4 million. Between 1998 and 2008, according to New York City tech advisory firm Nemertes Research, the “virtual workforce” grew by 800%.
Still, you’re right to cast a skeptical eye on job ads that make lavish promises since, as with any fast-growing and hard-to-regulate field, this one has attracted its share of con artists.
So how can you tell the good guys from the bad? Researchers at RetirementJobs.com, a job site specializing in employment opportunities for people over 50, recently put together a guide to working from home, available online to its members, that includes 10 warning signs of a possible scam. Beware of “employers” who:
• Don’t clearly describe the work you would do.
• Require advance payment for a “starter kit” or “handbook”
• Won’t allow you to speak with an actual person
• Promise high earnings for little work
• Rely on testimonials depicting attractive, happy people or families
• Depict lavish homes, cars, and boats
• Feature large quantities of money in their ads
• Have a record of complaints for fraud (Check the Federal Trade Commission’s web site, as well as state counterparts.)
• Promise to eliminate your financial problems
• Where the owners or principals can’t be identified
“It all seems like common sense,” the RetirementJobs.com report notes, “but common sense often goes out the window when you’re desperate or just a trusting person…. Only about 1 in 100 work-at-home opportunities is legitimate.”
In other words, if it sounds too good to be true, it probably is.
Nevertheless, starting with a list of about 500 widely advertised work-at-home positions, RetirementJobs winnowed 111 companies offering bona fide opportunities in 18 areas, including health care, IT, sales support, and personal care. Some are well-known, like Avon (AVP), Tupperware (TUP), and Mary Kay, but most are less familiar.
In the customer service category, since you asked, the guide lists 8 legitimate employers. In alphabetical order, they are AlpineAccess.com, Arise.com, Convergys.com, CustomLoyal.com, MedQuist.com, VIPDesk.com, WestAtHome.com, and WorkingSolutions.com.
The steps involved in starting a real home-based job are similar to those you’d take for an in-person position, notes Pamela La Gioia, including undergoing an application, screening, and interviewing process (usually online or by phone) and filling out the necessary tax paperwork.
La Gioia runs TeleworkRecruiting.com, a site she started in 1999 that matches virtual workers with more than 1,800 employers that have been vetted in advance.
“A real job does not ask you to pay them to train you, or for the materials you’ll need to do the job, or for information about the position,” she adds. “You don’t pay them. They pay you.” If you stick to that rule when considering possible jobs, you can’t go too far wrong.
One word of caution about seeking home-based work in order to spend more time with your kids: La Gioia says that many people harbor unrealistic notions of how easy it will be to combine child care with job duties.
“Small unattended children do not mix well in a work setting, whether on site or at home,” she says. La Gioia recommends lining up babysitting help just as if you were going out to an office. Trying to concentrate on work and on kids simultaneously “inevitably causes work to be of lower quality, which quickly becomes apparent to employers.” Noted.
Talkback: Have you ever taken a home-based job? How did it work out for you? Leave a comment below.