Simple brine for pork, poultry, salmon or shrimp

1 cup kosher salt

1/2 cup sugar

1 gallon cold water
  Dissolve salt and sugar in water. Soak pork chops or chicken pieces in brine for 1 to 6 hours, or overnight. Turkey will take at least 12-18 hours. Salmon and shrimp should brine for no more than an hour. Drain and dry thoroughly. Proceed with your grilling or roasting recipe.

Additions/substitutions to brine can include: 

Orange brine for pork and poultry

1 quart vegetable stock

1/2 cup kosher salt

1/4 cup dark brown sugar

1 teaspoon black peppercorns

2 bay leaves

1 quart orange juice

2 quarts ice water

Bring 2 cups of stock, salt, sugar, peppercorns, and bay leaves to a boil. Stir to dissolve salt and sugar. Add remaining stock, juice, and ice water. When mixture reaches below 40 degrees, add meat to be brined, and keep in a cool place (below 40 degrees). Brine for 8-24 hours. Remove meat from brine, pat dry and cook as desired.

Source: Alton Brown's I'm Just here for the Food