You have just started a new workout routine and then you get ill. What do you do? Do you keep on exercising? Do you stop your workout and take a week off to recover?
It depends on how ill you are. If you are seriously ill or injured then you should definately stop exercising and recover first.
If you have a fever, aching muscles (other than those caused by exercise) or a chest cough then you should avoid exercise until you get better.
However if you symptoms are all above your neck (runny nose, sneezing, sore throat etc) then you can exercise if you want. I would suggest you do a less intensive workout than normal though (go for a walk or a slow jog or bike ride).
In fact if you do have a cold and the symptoms aren't that bad then exercise may help you. Exercise has been shown to improve your immune system which can help your body fight off an illness.
The key thing is to listen to your body. If you are really struggling then do less intensive exercise. Increase the intensity back to your normal level as you get better. To help you while you are recovering make sure you include lots of chicken soup, ginger (I make fresh ginger tea) and garlic in your diet (all of these help improve your immune system).