When using a BBQ smoker, you need monitor the heat inside the smoker chamber.  To do this, use a thermometer inside the smoker to be sure that it's hot enough to cook your meat to at least 165 degrees.  This means your smoker should maintain an internal temperature of between 200 and 220 degrees. 

Once you're sure your smoker is hot enough, put on the meat. Because time will vary with every type and cut of meat you choose, use a probe style thermometer with big cuts of meat to be sure the meat heats to a safe internal temperature.  

Internal meat temperature probes are normally only used only with thicker cuts of meat like brisket and butts. They are sometimes used with chicken, but not very often.   When inserting in butts, make sure it does not touch a bone.  For chicken and ribs, you want to rely on your BBQ smoker's cooking chamber temperature and a timer.  A simple instant read probe can back you up on the chicken if you want to be sure it's done. 

I prefer digital probe thermometers, because they alert you when the meat is ready.  Please resist the urge to remove the smoker's lid during cooking, as this will dramatically decrease the internal temperature and thus, prolong the cooking process.

The importance of maintaining a proper BBQ Smoker temperature cannot be overstated.  Miss this one, and you'll be heading to your local barbecue shack's takeout window with your tail between your legs!  So get smoking. Just use a thermometer or two!