Per chef Michael,
Brining has been done for thousands of years. It helps to not only preserve meats but also to retain moisture. Meat contains fibres that hold in the water content but cooking will tear these fibres and allow them to dry out. Too much cooking of meat and you wind up with something like "jerky" hence the brining. It forms a web-like network that encapsulate the meat to hold in the moisture. When exposed to heat in the oven, this web expands and forms a barrier to stop the moisture seeping out.
Basic recipe for brining a turkey:
Use a small outdoor cooler, like you would bring to the beach. Place bird breast side down inside. Mix 2 pounds of sea salt in a gallon of fresh water and mix. Then add one cup of sugar, honey, maple syrup or something sweet (I used honey) and mix again. Pour over bird. Add 2 additional gallons of cold water to cover bird (more, if necessary). Let it sit in solution overnight.
Before cooking, thoroughly rinse bird inside and out. Place on rack and roast in preheated 400 degree oven for one hour and then turn heat down to 300 degrees to finish cooking. Do not stuff bird as the open cavity allows the heat to penetrate and cook more evenly. No need to baste thanks to the brining. When cooked, let bird rest on counter (place foil wrap over bird to retain heat). Carve and enjoy.
I will add my recipe for stuffing in the recipe thread. My family has been using my recipe for about the past 10 years.