There is two variations of Dumbbell raises shown here: First is your when your knuckles are facing outward towards the side of your body ,then raise your arms directly in front of you up to your shoulder height. Then second one is facing your knuckles to the front of you facing up towards the ceiling bringing dumbbells straight in front of you. Only difference is the positioning of your hands but the motion is the same. Try to go for about 10-12 reps on each exercise and take at least a minute break in between the two.