Stretching is an important part of fitness and exercise. It's good to stretch a little before and a lot after exercising. If you stretch after exercising, it increases your flexibility and your range of motion.
Be sure to stretch any particular muscle groups that were used during your exercise time. It's very wise to make stretching a habit, along with your actual workouts.
Don't bounce when you're stretching, this could lead to damaged, strained, or hurt muscles.
And always remember to breathe while stretching.
If there is any pain when stretching don't continue the stretch.
Be sure to hold the stretch for 15 or 20 seconds to make sure the muscle is properly stretched.
Here is a good picture I found online of a some stretches I do on a daily basis after my workouts.