How long are you contagious when you have a cold, and how long does it usually last?
Well, this can vary, as the course of the common cold often varies among different people and even from incident to incident. But as a general rule, if you are coughing, sneezing or having a runny nose, you can assume that you are still contagious.
Both people who have colds and people who are exposed to others who have colds should practice strict handwashing. That is the best defense against spreading germs.
Here are some links that might be useful to you:
7 Everyday Things You Should Avoid Sharing
6 Things With Unexpected Germ-Killing Power
10 Facts About Treating the Common Cold