Do a background check. Look for a physical address (not a Post Office box), request a catalog by mail, or call and talk to a company representative. Find out what other shoppers have to say about an online store on comparison sites such as Epinions or Bizrate. These sites have customer evaluations built into their design with a number of smiley faces or stars. Review their shipping methods and policies to determine what carriers they use, their shipping rates, and if they provide tracking and insurance. Also find out where they ship from—goods are sometimes sent from international locations, which require customs and extra time.

Most Important: The company should only require personal information that's necessary to complete the purchase. You will probably enter your credit card number, address, and telephone number. Be wary if they ask for other information such as your Social Security number, bank account numbers, or your mother's maiden name.