If you desire to improve your running performance and yet minimize injury, then there are a few eseentials to keep in mind.
Purchase good running shoes from a reputable brand. My personal opinion in that Asics, Addidas, New Balance, and UnderArmor make the best running shoes.
2. Landing on Feet
Run on the balls of the feet, never the heels. This will greatly reduce stress on the joints while building the calves.
3. Foot Positioning
Keep your feet pointed forward, never in or out. This will increase your speed, efficiency, and reduce injury incidence.
4. Arm Motion
Never let your arms and hands stay stationary while running. Your hands should pass by your hips and almost touch your face. You should never leave your hands open or clench your fists. Instead, cup your hands.
The faster you move your hands, the faster you will run. Also, the more you increase the distance of your arm stride, the longer your actual stride will be. Upper body coordination is critical to maximize the running experience.