A good director knows everything about making films -- or at least can fake it. That means you should try to learn as much as you can about the craft of your cast and crew. Attend acting classes (you can monitor the class if you are shy) to learn what actors go through. First-time directors often have a notoriously bad time talking to actors and conducting rehearsals, so put this at the top of your list. Learn about editing and photography and art direction and sound recording any way you can -- school, books, seminars. The more you know, the more tools you have to be a real filmmaker.