Adapted from

Preparing the Chicken:
Place the raw chicken in a clean sink and remove anything inside the cavity (neck, giblets, liver, etc.). Thoroughly rinse the chicken in cold water. At this point, if you choose not to brine the chicken skip to the "How to Roast a Chicken" step.
Citrus Brine Recipe
120 oz (15 cups) water
6 oz (wt) kosher salt
1 oz (wt) brown sugar
1 lemon
1 orange
1 grapefruit
2-3 sprigs fresh rosemary
1 bay leaf
1 tsp black peppercorns
2 tsp juniper berries
4 cloves of garlic
Heat 2 cups of the water in a small pot with the salt and brown sugar until the salt and sugar dissolves. Allow to cool for 5 minutes.

Toast the pepper and juniper berries in a small pan for about 30 seconds until fragrant. Crush the pepper and juniper berries in a mortar and pestle or with the flat part of a knife. Smash the garlic cloves. Place the chicken in a 12 qt pot, large bowl, or large zip lock bag. Cut the citrus in half and squeeze over the chicken. Drop the citrus into the pot. Add the smashed garlic, spices and herbs. Pour in the remaining 13 cups of water and then the dissolved sugar/salt mixture. If the chicken floats, weight it down with a plate. Cover and refrigerate for 8-12 hours. Flip the chicken every few hours.

How to Roast a Chicken
olive oil
Preheat the oven to 400 degrees.
If brining the chicken, remove it from the brine, rinse and pat dry inside and out. Discard the brine.
Rub the skin with olive oil and season with salt and pepper. Place the chicken on a v-shaped rack in a roasting pan in the oven. A 4 lb chicken will take 45 minutes to an hour. My 6 lb bird took about an hour and 15 minutes.
Check the progress after about 1/2 an hour. If some parts are starting to get dark faster than others, cover them with foil and rotate the chicken in the oven for even roasting.

At 45 minutes, start checking for doneness. An instant read thermometer is very useful here; cook the chicken until it reaches an internal temperature of 160 degrees in the thickest part of the meat, thigh or breast, it does not matter.
When done, remove from the oven and let rest for about 10 minutes before cutting to allow the juices to settle. Like a steak, if you cut it too soon, the juices will all run out and you will end up with a very dry chicken.