"Don't read the text on the slide. Make "ad-lib" remarks or supportive commentary about the slide. This gives students additional information about the material that is being presented." This is the single most important and most abused behavior in the classroom today, even amongst experienced instuctors. It is incumbent on every instructor to make sure that they don't fall into this trap. There is nothing wrong with allowing the students to read the slides themselves without hearing the sound of our own voices. I would even go so far as to suggest that you appoint a student the responsibity of pointing out if you start reading the slides.