Does anyone have a list of the responsibilities that come with it?
Welcome to the group!
There are not a lot of rules, as I understand it anyway. The main responsibility is to look at the "Uncommented Photos" that have been submitted to this site and give them your "critique" Inspiring of course. Now as a GS when you open the galleries you will see the word uncommented, click there and they will open up.
Also in the forums there is a section for GS which you will now have. And there is a thread on this question.
Again Welcome, I'm sure you will enjoy being the first to see and comment on all the wonderful pics the members submit