Finally got around to making a beer can chicken so the following is the recipe/pictorial journey.
Start the charcoal! If you have gas the ideal is a three burner so the middle can be low with the outside hot.
Prep the bird. I just use salt and pepper. Season liberally.
I use a beer can holder but instead of a beer can I use a half pint mason jar with water.
Next up... truss the chicken. Use about 3 feet of butchers twine. I secure the legs first then bring the twine up to the back, tucking in the flap of skin then crossing the front. Tucking in the skin seals the top trapping the moisture in the bird. Jacque Pepin has some great videos on YouTube showing how to truss a bird.
On the grill... Arrange the coals in a circle around where the bird goes. I put two coals directly under the bird to help the water in the jar heat up for steam. Watch closely for the first 1/2 hour to make sure the skin doesn't burn. Move coals in or out to adjust the heat.
I put a thermometer in the thigh. I find that beer can chicken can be a little under cooked in the thigh even if the breast is done. I cook to 175.
I check the chicken every 20 minutes or so to make sure the skin is not burning. The beauty of charcoal is the temperature slowly decreases slowing the cooking process. I pull the chicken off when it hits 175 in the thigh. Check the breast to be sure (165). Usually 1 1/2 - 2 hours. I rest the bird in a tent of foil for 10 minutes. Then cut up and enjoy!