There are many different types of CO and Smoke detector so make sure you know the details of your specific type and get familiar with it’s operation. These are just some basic guidelines.
You’ll need to make sure that every bedroom has a functioning smoke detector with functioning batteries, as well as one in the common area of each level. Check the batteries frequently and make sure the detectors are working. There should also be at least one functioning CO detector on each level. Make sure to refer to the users manual for your specific detectors to determine placement and functionality.