Long tossing/Arm strengthing with weights

I am constantly wondering about the period of time regarding on how long does it take to achieve arm strength? In addition, what are the various weight lifting exercises that are suitable for this? How often do I have to perform this on a weekly basis?

Chuck this into the Workout section then look at the megathread and some pitching logs (yankeesneeddice-k has a good weight program). Listen to what kc86 says - he’s the expert.