Whats the quickest way to build muscle?

Iv just started going to the gym, im trying to put a little bit more muscle on... mostly upper body but of course i wanna do my legs too. iv been told if i go to the gym like twice a week and do quite hard workouts ill rip my muscles and theyll reheal bigger. i know to do a reasonably comfortable weight so i dont do any damage but is there anything else that might help me? and help would be appreciated... THANKS! :)