I'd personally use only breast milk. And you're definitely correct with no juice (which is mostly sugar ... see Guidelines for offering juice to babies). See more info on water here ... Offering water to breastfed babies, which states:
For babies past the newborn stage
Too much water can interfere with breastfeeding because it fills baby up so that he nurses less. Babies need the nutrition and calories in breastmilk to grow - water has none of these.
Breastmilk has all the water your baby needs, even in very hot weather.
When your 4-6 month old baby is learning to use a cup, giving him a few sips of water a couple of times a day (no more than 2 ounces per 24 hours) is fine and fun.
Once baby starts solids, you might want to give him a few sips of expressed milk or water with his solids - some babies need this to prevent constipation.
Oh, and even us "not as new" mommies have lots of questions when it comes to our little ones!