How do I get buff (Muscular) and how long would it take?

I have always been kind of skinny and since i'm a senior in high school I want to start working out to get buff. By buff I mean big and muscular, not fat but big muscles. I don't know if genetics are in my side but how can I get really buff and get some good amount of size?? how long would it take? I would work out at least 5 days a week and eat healthy food high in protein. Right now i'm 17. 5'10 and 150 pounds.