What my kids are drinking is almost as important to me as what they are eating. You can drink away hundreds of calories and tons of sugar a day if you aren't paying attention. My kids are allowed three beverages - water, milk, and watered-down juice.
Water is the obvious one. We should all drink it, including the little ones. It seems to be the one most parents find their kids want the least, but the habit needs to start early! In between meals, the kids are allowed to have water (which both of them can fix themselves - yay!).
As for milk, we stick with organic skim. I can't afford to buy as much organic groceries as I would like, plus they aren't readily available in our small town, but milk is an important one for many reasons. I have no desire for my children to ingest nasty chemicals and growth hormones if they don't have to.
We are pretty picky about the juices we pick. ALWAYS 100% juice - you have to read the labels because so many "juices" contain added sugars and artificial garbage. I mainly buy the varieties that have vegetable juices blended in as well, such as V8 Fusion and Juicy Juice Harvest Surprise. While most juices are only high in vitamin C, these juices have a lot of Vitamin A and other nutrients as well because they use carrots, sweet potatoes, etc. I water them down because while they are 100% juice, they still have a lot of natural sugar in them. Real fruit is always the best way to get your daily intake!