What to do first

So you are driving down the road and you notice the check engine light on. "what to do". Lets turn off the radio and cell phone and pay attention, do you notice anything? Gauges, noise, engine run ok? Now if you have had experience with this light in the past, then you no what it means, if not pull over and lets get out the owners manual and find out. A good rule of thumb is if the light is red pull over now, yellow or amber and on steady u have some time(don't panic). If the light is flashing u need to find a shop soon.