Hi there,
So many good comments so far, and here are just a couple additions that have worked for us this first year and 1/4.
First of all, put the carseat in the crib and have him sleep upright, strapped into the seat. This was the BIGGEST help to our daughter when she was so severly congested. The cool-mist humidifier in the room nearer to the crib than not, is also key.
We found an amazing device that trumps the bulb syringe by a mile - it's the Nose Frida (sp?) - basically a snot sucker. Easier to use, more effective, and no chance of hurting a little one's nose as it doesn't go up the nose. Ask your specialty pharmacy, or you can find it online easily. We found ours at our local pharmacy, amazing product - use after saline drops/spray as it will help liquify the mucus. Do before eating and sleeping, will help a ton.
We weren't suggested to use medication (ex: Benadryl) until just recently at 16 months, as it's clear our daughter does have seasonal allergies, and 9 out of 10 times the mucus backs up and causes either one or two ear infections, despite not having a cold virus. The cough sounds like a bad thing, so don't let it go more than another day or so without getting his lungs listened to, just to be safe.
Hope this helps! I am a first time Mom.
~J