not so funny... my weight 46 and height is 168.skinny (ectomorph) too right...
what i do now consume 5-6 meals a day. i means healthy food that contain carbs and protein.
get enough sleep 6-8 hours. lastly, doing some workout 3 times a week. the important part of all above is u need to be CONSISTENT!! after 2-3 weeks i gain some mass around 3 kgs

read stickies in bodybuilding section, there are a lot of good info about the workout u should do.
good luck...