I start with a full ring of charcoal mixed with about 5 fist sized chunks of wood. I create a small indentation in the middle of ring. Into the middle of the of the charcoal indentation I place 10 lit, ashed over briqs.
Bottom and top vents wide open. Once the grate temp reaches 195 degrees I close all the vents half way. As the temps start to rise a little at a time I close the bottom vents until the temp reaches the 225 degree range. At that point I let the WSM chug along for 30 minutes. Then I put the meat on. Some people will take the temp up a little higher than the desired cooking temp so when they put the meat on the temp doesn't fall that far. I don't normally worry about that.
Keep in mind that I do not use water in the water pan. I use a foiled 14 inch terra cotta saucer. This, in my opinion, allows me far greater control over my temps than using water.
Keep practicing, you'll get it...