5 mins of walking before weights is great for waking your body up and getting blood flowing.
i always do cardio after weights. 45 mins to an hour. varies on how i am feeling. don't take a shake or anything else until after cardio. if you have it in your head that you must take something right after you lift or you will burn away all your muscle
then take some bcaa's.
walking fast, 3.7-4.0, on an incline of 10.0 or higher, will do wonders for your calves. yes it burns and every step hurts, but if you do a few sets of calf raises before you do cardio, the pain never shows up and you will see great definition in your calves.
anyways, all of this is what works for me. try it out!