As more people opt to work from home there is both a proliferation of scams and commensurate bad advice on how to address it. Such as this article in the Seattle Times:

Those who say you can earn a living working at home with your personal computer are engaging in wishful thinking, or they're trying to sucker you into a pyramid scheme in which you spend your day e-mailing similar offers to other potential suckers. These "jobs" are nothing but a racket. Be careful.

An annoying overstatement, but it does pay to be careful and know who is offering the position and their reputation.

The FTC has lots of articles on how to avoid work at home scams. The Better Business Bureau is also a good place to check out the credibility of an organization. And, I would be remiss if I did not mention our own website, FoundValue, where we are attempting to put together a valuable resource for home-based work of all kinds (including some of the unpaid but work-like activities such as homeschooling).