While milk makes tasty protein shakes, most people are lactose intolerant (whether they realize it or not). On top of that, the quality of most dairy products here in the U.S. is just horrible.
I use rice milk instead in my pre- and post-workout shakes because it tastes good and it’s fairly high on the glycemic index (it falls somewhere between 70 – 80).
It has 24 g of carbs per cup, so I do 1 cup with 1 scoop of protein powder before working out, and I blend 2 cups with 2 bananas and 1 scoop of protein powder after working out (along with whey protein, creatine, glutamine, fiber, and cinnamon).
Many guys use processed carbs like dextrose powder and waxy maize for their post-workout carbs, but my body feels much better getting carbs from rice milk and fruit as opposed to processed sugars.