The Flu is a very preventable sickness and a few simple steps can keep you from contracting it or spreading it to others.
The best way to prevent the Flu is to get vaccinated if at all possible. Otherwise there are some very simple common sense methods to prevent spreading.
Cover your nose and mouth when you sneeze: just like your parents told you when you were a kid.
Try to sneeze into the crook of your elbow; this keeps germs off your hands and other people.
Wash your hands: Washing your hands with soap and water or an alcohol-based sanitizer will kill most germs.
Avoid touching your eyes, nose, or mouth: Germs can easily enter the body through these areas and avoiding contact with them will help you from spreading germs into your system.
Self-assessment and bed rest: If you believe you are sick or becoming sick stay home. Stay home and away from others until having gone 24 hours without a fever or signs of a fever (without the use of fever reducing drugs).