Treat the beet tops just as you would spinach or any other greens.

After thoughly cleaning, Cut into hand-size pieces. Then you can boil them or fry them with your choice of seasonings. Bacon or ham is good. Maybe chopped garlic, salt and pepper, a little plain sugar. Experiment. Just don't overcook. They should be limp, but not mushy. Some people like to douse them with a shot of vinegar.

The beets themselves can be boiled just as you would potatoes. Don't let them get too mushy, either.