what should i do and how long and how often should I do them for

I don't want to bulk up heavily. Just get ripped and add some beef around my upper arm (triceps/biceps).
My height is 5'7. Is 24 lbs (12kg) per dumbbell too heavy?

i am 14, boy, 125 pounds. i have access to 5,20,30,40 pound dumbbells. i currently do 20 reps of 20 twice a day. is that good? for a standard dumbbell bicep curl?

I don't want to bulk up heavily. Just get ripped and add some beef around my upper arm (triceps/biceps).
My height is 5'7. Is 24 lbs (12kg) per dumbbell too heavy?

I weigh 10 stones and i am 5ft 9inches, how much should i be lifting with my right arm, with 1 dumbbell