Know your subject matter really well and practice reading to your dog or just out loud to yourself ahead of time.
Look over the heads of the class at a point on the wall in the back of the room. The class will think you are looking at them, and the teacher will think you are looking at your audience.
Don't notice any reaction from the class. Their reaction doesn't matter, but it might make you feel more nervous.
Concentrate on what you are saying rather than how you are saying it.
Don't try to keep from stuttering as that will make you stutter more. If you stutter, just let it happen.
Maintain a steady pace, not too fast, and don't get in a hurry to "get it over with."
Speak in a relaxed manner and pause every so often.
Start into words easily keeping your lips, tongue, and jaw relaxed.