This depends on a number of things..
a big one would be your goals.
Obviously the amount of protein you want in your diet for the majority should come from actual food.(MEAT) So the shakes are a good substitute for this and serve their jobs well. As far as the Pre-Post Workout question, lots of people around here (myself included) prefer and use Surge. It can be split up before/during/or after. You can find it in the T-Nation store.
Hope that helps.