• Know who you're dealing with
  First, ask yourself how you heard about the site, counsels Walter Effross, an associate professor of law at American University's Washington School of Law. "Did you see an ad in The New York Times or a respectable magazine -- or a spam e-mail?" he asks rhetorically.

You can feel pretty confident in nationally known brands that advertise on television, in newspapers and magazines, and on Web banners.

At the same time, a little storefront on the Web might be just as trustworthy and efficient as the big boys. Does the site provide phone numbers, an address and an e-mail link? Those are indications, but not guarantees, that the company is on the up-and-up.

• Insist on secure transactions
  The good news is that it is relatively safe to use a credit card on the Web if you are buying from a reputable seller. The bad news is that it's not absolutely safe. It is possible, though unlikely, for a hacker or a dishonest employee to steal your credit card number over the Internet.
  Follow these safe sense tips to protect yourself:
  • Enter credit-card information on secure server pages.
  • Choose good passwords and don't give them to anyone.
  • Use credit cards instead of debit cards.
  • Confirm whether your order was taken correctly.

  For safety's sake, you should enter credit-card information only on pages that are on secure servers (or SSLs, in the jargon of the Web). Usually your Web browsing software will alert you when you load a secure page and when you leave one. If you are on a secure page, you should see a tiny icon of a locked padlock or an unbroken key in the status bar at the bottom of your Web browser window.

  A secure page encrypts the information -- puts it into secret code -- so that even if someone intercepts the data, it can't be read.

  Usually if you're buying stuff over the Internet, the merchant requires you to select a user name and a password. When you choose a password, write one that can't be guessed easily. Stay away from the names of pets or family members and birth dates. And you wouldn't even dream of using your Social Security or a credit-card number as your password, right?

  Most online merchants reply to an order by e-mailing a confirmation notice that lists the items and quantities bought. Check that carefully and respond quickly if there has been a mistake.

  Generally, it's safer to use a credit card than to use a debit card. With some debit cards, you could wind up paying for the entire loss if a crook taps into your account. On the other hand, you are liable for up to $50 if someone uses your credit card fraudulently.

• Pay attention to terms and conditions
  Many retailers on the Web have a "terms and conditions" link at the bottom of the home page. You have to look carefully; the type usually is the size of an ant's eyelash. But some of the most important information is behind that link -- information about return policies, for example.

  Last December was the shopping season when Internet retailing reached the big leagues. When people wanted to return gifts bought through the Internet, they often had trouble figuring out how to do it, says Russ Bodoff, senior vice president and chief operation officer of BBBOnLine.

  A terms-and-conditions page might have information not only about return policies but also about shipping rates, sales taxes, cancellation policies and payment options. Pay close attention because sales tax and shipping charges can differ.

  Mark Elliott Budnitz, a professor at Georgia State University's Law College, recommends that you print out key pages and read them on paper to make sure you completely understand. For most people, reading comprehension is higher on paper than on screen.

  "When you're doing business on the Internet, it really is different," says Budnitz, who belongs to an American Bar Association working group that is studying consumer protection in cyberspace. "You don't have written pieces of paper you can look at. So an important consideration for consumers is if you can print something out."

  Sometimes a page is built in such a way that you can't print it. Be careful if that's the case, Budnitz says: "A lot of consumers think if it's on there and it looks good and official, the government much be watching," he says. But regulation is not pervasive on the Internet.
  

• Check what other people say about the company
  You can see if a company is registered with BBBOnLine. The presence of the organization's reliability seal indicates that the retailer is a BBB member in good standing with a satisfactory complaint handling record, Bodoff says.
  
  You don't have to use technology to check up on retailers. Perhaps the best way to discover a store's reputation is to rely on non-computer-mediated interpersonal communication.
  
  In other words, word of mouth.