Please tell how to put some flab on my bones?

My height is 6'2 and my weight is 75 kgs. My problem is that i am very skinny. From sideways it looks like my big head is placed on a small stick. I do a lot of running but that doesnt help much. So excluding my legs my upper body is very skinny. Please help me. Oh and please suggest me specific exercises, my knowledge in exercises is very limited. I am 18 yrs old.