To cook the beets, you can either boil them in salted water, or wrap them in aluminum foil and roast in a 400 degrees oven until tender.
Place cooked beets in two separate bowls (one for the red, the other for the yellow). In a small bowl, whisk together vinegar and olive oil. Add caraway seeds, and season with salt and pepper. Divide vinaigrette between beets. Cover with plastic wrap, and chill overnight.