Start in the standing position with a slight bend in your knees holding the dumbbells at the top of the handles so your thumb and pointer finger are touching the plate. Be sure to maintain a neutral spine, keep your wrists straight, elbows in front of your hips and your arms slightly away from your body while performing the exercise. When you raise the dumbbells only lift them so that your elbows comes to a 90 degree angle. Any higher will disengage the bicep and the weight will transfer to your shoulder. Lower the dumbbells slowly to the starting position and repeat.
NOTE: You don't have to keep your feet together, it is just more comfortable to me when I keep them together. Some prefer shoulder length as well.