C.M.
Welcome to the club! Everyone I know is dealing with them right now. We turn first to holistic remedies in our family and believe that Vitamin C works wonders. Also, I have 2 facial saunas and I have the kids (ages 7 and 3.5 yrs) use them every night for 10-15 minutes - sort of like a turbo-charged humidifier. It cuts down on the night time coughing and congestion.
When there's lots of sinus stuffiness, we use saline nose sprays and a neti pot. My 3 yr old won't use it yet, but my 7 year old can.
Good luck!