Your list is your fanbase, your people, those on whom you will call for support and enthusiasm with all your future endeavors, who will continue to follow, study with you, perhaps eventually collect, and share and spread the word about you.
Viewed in light of these goals, a newsletter shifts from a being task to complete to a resource to nurture. It helps to be consistent, responsive, and real. I think of my newsletter as a conversation developed over time with someone I would love to sit down and catch up with over coffee. With each newsletter, you are creating a conversation with your readers. Individual"comments"can be short, topics can vary.
Above all, the conversation has to stay interesting. If this fills you with fear, relax. It's simpler than you think.