Should carbon monoxide detectors be installed in rooms containing gas appliances?
No, you don't want to install CO detectors in the kitchen or garage, or too close to any gas-burning appliance. 

You want CO detectors if you have gas appliances, but (somewhat ironically) you don't want to place the detectors close to those appliances. This is to reduce the number of false positives you get from the detector.

CO detectors should be placed on each level of the house, in each bedroom or just outside the doors if two or more bedrooms are close to each other.