Putting the wood chunks under the charcoal before lighting it works really, really well.
Here's the deal. I love slow and low cooking. After spending years on slow cooker and sous vide recipes smoking food was clearly going to happen. I bought a really cheap bullet smoker earlier this summer and wrote a few pieces about using it while camping. The food was amazing, however, the cheap bullet smoker pretty much fell apart after 4 uses.
I bought the Weber. The Weber Smokey Mountain really is wonderful and I wish I'd not bothered with the cheap smoker. Construction and materials quality are 1000x better.
My brother is a chef and runs several restaurants. When he relaxes with cooking he makes bbq on an offset smoker. While he was teaching me about smoking vegetables, fruit and meat that offset smoker would eat tons of wood. I was under the impression you needed to keep adding wood to get stuff to have that smokey flavor.
The bullet smoker is a very different animal. You do not need that much wood. You do not need to adjust or dick with the fire very often, and if you put in enough coals at the start you can pretty much get through 12-16 hours of smoking a brisket without adding fuel.
If you keep adding chunks of wood like it is my brother's offset smoker you end up with over smoked food.
I still ate it, but luckily didn't have to share with anyone.
Reading online there is a lot of advice. Turns out just putting a very few chunks of wood under the coals before you light them works perfectly. My 18.5" Weber has 3 air intakes at the bottom. One fist-sized chunk of wood in front of each intake works really well. I tend to find that smoldered bits of the wood chunks so placed survive after the unit has burned down.
World champion BBQ guy Harry Soo's directions have worked perfectly for me:
I want to explain the basics of fire control in a barbecue pit. Regardless of the pit you're using, they all have three major components that you'll need to learn to control to maintain proper cooking temperatures: 1) the air intake, 2) fuel you're using, and 3) the exhaust vent/chimney. I use Kingsford Blue briquettes so my description assumes you use the same fuel. If you use something else, your mileage will vary.
I've used KF Blue since I started competing in 2008 and with over two dozen Grand Championships and 80+ first places including a first place USA in chicken in the Kansas City Barbecue Society Team of the Year 2012; I know KF Blue works well. Besides, I buy them on sale in the summer months for half price and stockpile them for my classes and contest year where I use over a hundred 20-lb bags annually. Yes, I do use other types of fuel like lump charcoal and pellets but I like to compete using KF Blue (no, they are not my sponsor) because I can fly into any city in America and drive my rental car to Walmart to pick up one bag of KF Blue and win a Grand Championship.
In the WSM, there are three circular intake damper vents at the bottom that can be opened or closed as needed to allow more or less air to enter the pit. More air and the temperature goes up and less air causes the pit temperature to go down. The circular fire steel fire ring holds your charcoal and you can adjust the amount of charcoal depending on how long you need to run the pit.
If you run it for chicken (2 hours), you only need to fill the ring about 1/3 way. If you want to cook ribs (6 hours), you will fill it about 2/3 way. If you're cooking brisket and pork butt (> 12 hours), you want to fill it all the way going past the top of the charcoal ring until it is overflowing. Be sure to remove the excess briquettes that have fallen over the side of the charcoal ring. Do a bit of Jenga and create a volcano shaped crater at in the middle of the overflowing mound of charcoal by removing excess briquettes and returning them to the charcoal bag. When you're ready to start cooking, carefully dump a half charcoal chimney of lit briquettes into the crater. Over the next 12-16 hours, the briquettes will burn gradually outwards as the temperature stays constant. I cook my long haul meats at 250F and everything else (chicken, ribs, tri tip, beef ribs, etc) at 275F.
Weber Smokey Mountain Cooker 18 Inch Smoker via Amazon