1. Ensure that you're entering your payment details on a good site. Search for "https://" within the URL from the site that you're trying to buy something from. If you don't see that or no symbol of any website security, then it's probably a wise idea not to trust those people along with your account information.
2. Before you start your online shopping, ensure that you've got up-to-date antivirus software. Shopping online is a hotbed for suspect websites. Some people build stores with the goal to infect your computer with malware. It's best that you simply take precautions prior to visiting any stores, no matter how reputable you feel they are.
3. When you find yourself making a purchase online, make sure that you use a credit card to pay for the transaction. Charge card users are protected against fraud by federal law and are only liable for $50 in these cases. Some card agencies will even go so far as to wave the $50 for you, meaning that you will not be out of pocket.
5. When you're shopping online you should be sure that you know who you're buying from. If you're buying with an online auction site, only order from people that have positive feedback. On other sites look to see should they be a reputable company by trying to find reviews on them online.