Go to media center of your school and find out if you have the equipment needed for production. Meet with your work group. Assign particular responsibilities to everyone: two people in charge of operating cameras and microphones, another one to operate VTR, two or three people to find news stories, who could also be newsreaders. Usually, national TV newscasts require more people, but for your school you can start with this number of collaborators. Also, select the duration of the newscast. Thirty-minute newscasts are a great way to begin with.
Look for important news stories. This is really a crucial issue, because your team members must use their critical thinking skills in order to separate relevant news from trivial material. Like Peter Parker's uncle said to him "with great power comes great responsibility." Whatever you're saying on air will have repercussion in your audience, so be careful and use ethics at all times.
Look for testimonials, even if you're trying to find proof, evidence, or just registering the student's opinion about an issue. This way, the audience will know that you are open to different perspectives, and not just a dictator.
Be part of edition process. You don't need to be necessarily next to the person on charge of VTR, but you have to let him know the right procedure. Images must adhere to reality and not distort, or use suggestive effects, even if they're intended as a joke. A simple rule is: when in doubt, don't.
Instill confidence in your team with a calm attitude. Even if the worst thing just happens, everybody will expect you to be calm, and help them to solve problems. Being a producer is a hard work that requires a lot of talents, but the most important thing you need is passion for what you're doing.