Warm-up and Stretch before and after you run

Before beginning your run, warm-up and stretch.
To warm-up, take a brisk walk or easy jog for 5 minutes.
Then, take 5-10 minutes to stretch.
The following link illustrates the stretches we used during this morning's workout:
http://running.about.com/od/stretchesforrunners/tp/stretchesforrunning.htm
When you finish your run, take 5-10 minutes to cool down with a brisk walk or easy jog. Finally, stretch your muscles again.
***The rule of thumb when it comes to stretch is this: Pain is not good. If the stretch hurts, you're straining your muscle. *** Keep your stretches in a comfortable zone.