Thought I would add in to the discussion. I agree totally with San D about ventilation. I have found that the commercial glazes are very smelly during the fuming stage. This is another reason why I turn the kiln on when I am leaving school and leave it on overnight -- no one smells the fumes. By the time I come in the next morning, the fuming is finished and there is no odor. We all need to be aware of dust and odors with the materials we use, this is especially true with clay. Clay dust is awful and accumulated inhaling of the dust is very bad. I have a ceramics class where during first term the students are learning to mix glazes and do other clay and glaze tests. They are all required to wear good dust masks. This is an expense that the school has agreed is necessary to have spent to provide appropriate masks to protect the students. If we don't teach them how to take care of themselves while using some of the most fun materials in the world, we are not teaching them well.
I always fire up my kiln during the day, mainly to make sure that it shuts off when it reaches temperature. This is why sight cones, inside the kiln, are very important to place. Timers are another way to fire a kiln but being a potter, I have always used the standard method with cones. Computerized kilns are very cool and having one in a school is a treat. You can program it to "soak" at certain temperatures to bring out even more interesting effects with glazes, commercial or home made.
Tara, I hope this discussion has been helpful and good luck with your firings!