i just started taking my casein as well.
I only use 1 scoop (this shit is expensive) 23$ for 24 servings. about a buck each.
I would ONLY take casien at night prebed, or as a Meal Replacement, for after your workout, like ingrim said, jugg down a WHEY protein, since your body needs to be able to absorb the protein ASAP after a workout.
I feel i am getting leaner using the cassein,
P.S. As a meal replacement, i usually add 1 scoop vanilla cassein, 1 scoop of strawberry whey + Milk or H20+ANPB(if im bulking), tastes great, and i am getting the best of both worlds.