It depends on the kind of cooker you have. I have a drum, a 22.5 WSM and a hog cooker on a trailer. I never try and adjust my temp by using the exhust vents but use the intake. I always have my exhust vent wide open. On my drum and WSM I use about a half bag of charcoal to start and depends on what I'm cooking. More info would help.
Rating
How Much Wood To Use To Maintain Smoker Temperature by: Anonymous
Start out with a small fire in the firebox, and maintain it by adding a couple of sticks of wood every half hour, or often enough to keep the fire the same size. Allow for plenty of intake air so the fire burns clean, and adjust the exhaust vent so it's about halfway closed.
With meat in the smoker, monitor the temperature until it stabilizes. If it's too low, increase the size of the fire a bit, and let the temp stabilize again. Repeat until you know how large of a fire it takes to keep the smoker temperature where you want it.
You'll have to consider variables like outdoor temperature and wind, too. These will cause you to have to either increase or decrease the firebox fire size needed for the desired smoke chamber temperature.
