My son is a golf pro, and I took the GMP Fitness Golf Conditioning Specialist training program. The key is strong big muscles - legs, back, chest, core strength - because you use your whole body in the golf swing, not just your arms.
Be prepared, because it's not easy! I would suggest you take lessons from someone with a video camera so you can see what you're doing wrong. You're smart to learn to do it right from the start so you don't have to un-learn bad habits.
You know I love anything Spri products makes, and they have a Gary Player Golf Gym, which my son is now using in the off season.
Just Do It! :7