When you feel a cold coming on try drinking some juice with Vitamin C and drink plenty of warm liquids such as warm tea with honey.
Take some over the counter cold medicine and take a nice steamy shower to help clear up any congestion.
Prop your head up on a pillow, get plenty of rest and use a humidifier in your room at night to keep moisture in the air.
Other than that there's really no cure for the common cold but just let it run it's course and like I said keep up on the Vitamin C intake to help boost your immune system which can sometimes prevent you from getting a cold.
Also wash your hands often using hot as water as you can stand and use antibacterial soap and wash your hands every time you blow your nose or at least before you eat any food.