Good advice from Colin. Just some stuff to add on the stretching front, don't stretch before you warm up. Stretching cold muscles is bad. I don't usually do any stretching beforehand, but if you choose to, keep it light and dynamic (not static stretching...save that for afterward). And when Colin says GOOD stretching, he means it. In order to see muscle length changes, you need to stretch for a while...like a total of 3 minutes at a time (go with say 6x30 seconds).