Although arms should not be a major part of the golf swing, they are definitely a part of it. You cannot swing the club without your arms. That said, remember that you do not want an “armsy” or “handsy” swing. Do whatever you can to take your hands and arms out of your back swing and overall golf swing. With that being said, we need to hold the club and how do we do that in the setup? The putting perfecter is a great training aid to make certain you are setting up correctly.
At setup, your arms should not be straight or extended. Your left and right elbows should be somewhat relaxed and bent. If you want to hold a 20 pound weight out in front of you, would you hyperextend your arms and try to hold it or would you bend your arms at the elbows? So, bend those elbows ever so slightly when you are at setup.
If you are right handed, your right elbow should be bent more and “behind” the left elbow. If you take a picture or video from behind, you would want to see your right elbow closer to your stomach than your left elbow. If you put an alignment stick at your elbows, it would be pointed slightly up and to the right of your target.
The reason you want your right elbow bent a little more, and lower, is it will allow you to “fold” that elbow on your backswing. Do not use your arms in the backswing, but understand that folding your right elbow under is necessary. The elbow should always stay between your shoulders through the entire swing. If you do not fold your right elbow during your backswing, there is no way you can keep your elbows between your shoulders.
You can learn more about The Correct Golf Swing here.