Having listed all these benefits of drinking freshly squeezed vegetable/apple juice, let me get to the actual juice. To make 3 medium servings of juice I use:
2 stalks of celery
1 small beet
3 apples (any sweet kind will do. I use Red Delicious)
And if you are feeling particularly adventurous, add a bit of fresh ginger, which is the best immune system booster (but really, just a little. It has a very strong taste for a child, especially).