Get as much rest as you can: If you only have a cold, and not flu, it's unlikely that you'll get away with cancelling everything and curling up in bed for the week. Even so, the more rest you can afford yourself the quicker your recovery should be. Sleep is your body's downtime, after all, and it uses this opportunity to run system checks and make essential repairs.
Inhale: Breathe in steam, from a hot shower, a bath, or a basin of hot (but not boiling) water. This can ease blocked or stuffy noses and even a sore throat. Adding a few inhalant drops such as menthol crystals or eucalyptus oil can also help, available from your local pharmacist.
Keep your strength up: Eat well, and be sure to drink plenty of fluids. Illness can rob your body of essential nutrients and vitamins; something you can effectively restore with a decent diet.
Make friends with the pharmacist: They can advise you what over-the-counter products are most likely to help make you feel better, and get you on your feet when it really matters.