Do any of you guys weight lift? I'm a fairly skinny guy, I'm kind of strong but i don't have much muscle mass. I'm wondering if you have any tips. All I have are 2 dumbbells weighing 15lbs each and I can't afford to go to a gym right now, maybe in another year. Anyway I basically want to build mass in my arms and upper body, mainly shoulders and forearms. All I have been doing are curls, pushups and sometimes behind the head working the triceps. I know nothing about weight lifting and the different strategies of how to lift and how much to lift, any help would be appreciated.