How to orient a whole chicken during roasting is a much-debated topic. A method that pleases all sides is to spatchcock or butterfly it -- cut out the backbone and flatten the whole thing, then cook it breast-side up until cooked through, resulting in a golden, moist and evenly cooked bird. But if your knife skills are lacking or you want that picture-perfect whole chicken, cooking it on both sides will get you the best of both worlds.
Which Way Up?
Roasting a whole chicken breast-side down allows the juices of the chicken to concentrate in the breast meat as the chicken cooks. But you shouldn't keep it breast-side down the whole time as it will result in a rather pale-looking chicken -- not the golden-brown roasted chicken you're expecting. To counter this, turn the chicken over about halfway through the cooking time to allow the skin to brown on top. Be careful when flipping the hot chicken -- use long-handled tongs or grab two wads of paper towels and handle the chicken directly.