Marcopollo. I'm sure you're a fake dude, but still, it might help others.... I don't mean to sound like an ass, but if you are that skinny and want to "gain", then eat a ton of clean foods and lift heavy. Period. Progressive resistance. It really is that easy.
Compound movements, no silly cute tricep kickbacks, and one arm dumbell BS, just bench dips pullups squats deadlifts presses rows... stuff like that. Keep increasing weight and EATING clean and in a year you'll be a different person.
Someone prove me wrong and I'll kick them in the fucking shins!