• Shop in the right frame of mind.

Don't shop when you're tired, under pressure, or distracted, the Better Business Bureau advises. You need to be fully "cyber-aware," it says. A clear head prevents you from getting hoodwinked into buying something online that seems to be too good a deal to pass up.

Do your homework on the vendor you're about to do business with. The BBB lets you run a background check on thousands of Web merchants at its site. You should do a Google search of the online store you're considering patronizing, to see what the Web community is saying about it. If the search results spit back vitriol, that should serve as a red flag to pass on that merchant.

Background checks are also advisable for online stores that you find using comparison shopping engines. Even if such a shopping engine gives a merchant a positive rating, you should do your own research and not rely just on ratings found on one site.

• Pay attention to details.

Check your browser's address window to see whether a Web site's "product checkout" page begins with 'https' instead of 'http.' Also check whether the checkout page displays a padlock icon in the lower right-hand border of the browser window. Both of these things indicate that the site is using secure encryption to protect your credit card information.

If an online retailer displays a seal from Truste or the Better Business Bureau, that's a good sign that the merchant in question is reliable. But be sure to click on the logo or seal to make sure it actually links to the BBB or Truste site, to validate that the seal is authentic. It the logo doesn't link back to the appropriate site, look the merchant up yourself on the BBB or Truste site.

• Make a paper trail--and check it twice.

Make sure to print copies of all online receipts so that you can check them against your credit card statement. You should also print copies of all guarantees and warranties.

Pay with your credit card whenever possible. Most credit card companies won't hold you liable for fraudulent purchases.

• Beware of charity fraud.

This is the time of year when charity fraud becomes popular with scammers. Charity scams spring up after disasters, but they also assume a larger presence during the holiday season. Be careful of charity frauds that use names that sound similar to legitimate organizations and may be using the logos of legitimate charities.

Check out any charity by going to Wise Giving.