Rob Sicc - Yes, wood is added from the outside on some smokers. On others like Cookshack, Smokin-it, and SmokinTex, the wood chunks are placed in the wood box which sits/slides over the heating element. You load it at the beginning of a smoke with 2 to 6 ounces of wood, load the meat, lock down the door and that is it. No need to open to add more. After a while you get used to cook times so opening the doors to check the food becomes infrequent. For ribs, I don't generally check till they've been in the smoker for 4 1/2 to 5 hours. For a large cut, like a butt, a temp probe inserted into the meat and running out the smoke vent to the remote lets me keep an eye on internal temperature. If I am cooking to an IT of 195 I will not open the door till it reaches 195. Sort of set it and forget it.
On the MES, chips are loaded periodically via the chip loader. Load it, push it into the smoker and rotate. It drops the chips onto a tray where the heating element burns them.
Some folks use the AMNPS and burn sawdust or pellets. They fill a specially designed tray or tube, light it with a torch, and once it is going good, slide it into the smoker, load the meat and lock it down. You can read about that on the numerous MES postings.