You can make authentic barbecue on a Weber charcoal grill. All you need to do is remember a few principles.
True BBQ cooking occurs with a very low temperature for a long time. True BBQ also incorporates smoke. To accomplish this on a charcoal grill you need to understand the correct amount of charcoals to add as well as how often to keep adding charcoals and wood chips.
A quick rule of thumb that I just came up with is to begin the smoking process with about 6-7 coals on each side. Take a look at the picture below, here I use Weber's indirect cooking baskets. Each basket has about 6-7 coals. When the coals are lit, I move the baskets to opposing sides of the grill and add wood chips. This will give you a perfect 250 degrees. Moving each basket to opposing sides allows you to indirect cook your meat. You don't want to cook authentic BBQ in direct heat or you will end up with burnt BBQ!
You will need to be able to maintain a constant temperature of about 225 to 250 degrees for proper smoking. Check out my page on maintaining temperature to learn a bit more about this. You will need to keep about 12-14 lit coals in the grill at all times to maintain this temperature. Below is a picture from a pork shoulder smoke where we opened the lid to add some more coals and wood. This picture was taken about 10 hours into the smoke. Don't be afraid if you see some flame ups with the wood when you open the lid - this is normal. You can soak the wood in water to help with the smoking and to reduce flame ups but no matter how long I soak my wood it still flames up when the lid is open!
Professional smokers make use of real wood burning smokers, rather than charcoal grills. But the purpose of this site is to make note that it is possible to make authentic BBQ on a charcoal grill. It takes patience and determination but it is well worth the hard work. One day I will upgrade to a real authentic smoker, but until then... my Weber Performer works just fine!
Check out this youtube video on smoking meat on a Weber charcoal grill for more assistance.