My son was exclusively breastfeed till 6 months, then I started adding in sippy cups of water and some solids. At about 9 months I introduced soy into his diet, which included giving him soymilk in a sippy cup a few times a week. At 2+ years now he drinks watered down juice maybe 3 times a week, soymilk 3 times a week, but primarily for his liquid intake he drinks water and nurses. He eats lots of other food all day long too.
From what I can remember, breastmilk (or formula) is all a baby really needs for the first year, assuming enough wet diapers, adequate weight gain, and reaching milestone achievements. Any solids or other forms of liquid are more for exploration then nutrition.