There are so many benefits to stretching, including your fitness and performance. In fact, those that have not tried a yoga workout would be shocked how difficult just holding a position can be. Here are just a few notes on stretching along with the mayo clinic video guide link.

Do I need to do a Pre-Workout Stretch

Make sure before you begin your stretching, your muscles are warm. Start witht walking, jogging, biking, running in place at a low intensity for 5 to 10 minutes. I see a lot of people walk into the gym and start stretching first. While they think it is helping, they are actually risking injury.

The Stretch

An obvious benefit of stretching is to help improve flexibility and range of motion. Over time, muscles become tighter and range of motion is minimized. This lack of flexibility can lead to injuries.
Often, the lack of stretching and tight muscles will contribute to poor posture. Stretching helps to ensure correct posture by lengthening tight muscles that pull areas of the body away from their intended position. Stretching the muscles of the lower back, chest and shoulders can help keep the spine in better alignment and improve overall posture.

One of the benefits of stretching and fitness is the increase in blood flow to muscles. You will have an increase in muscle recovery from stretching alone! So stretch not only after your warm up, but after you exercise as well. With improved performance both during activities and after, you should make stretching a key component to your fitness routine.
For more information, use this guide from the Mayo Clinic: Stretch Guide