Notes
I like a fair amount of lime juice to counteract the sweetness of the cranberry juice. If you use real cranberry juice (not cranberry juice cocktail with sugar added), you can omit the lime. Also, I have found Ocean Spray to be superior to the cheaper brands.
One other note, you may be tempted to try one of the Cran-This or Cran-That flavors. I have found these produce an inferior drink when compared to original cranberry flavor.