After reading through some of the other responses, they are all very good, my question is where are you teaching this class? If it is at your LQS you need to know what she has available for students to buy, and try very hard to encourage the brand that she carries. After all, you are being paid by her, using her space, etc. so it makes sense to me and I know that they appreciate the extra sales.
It is very important that you know what level of experience each member of the class has, so I always have each person in class introduce themselves, tell when they started quilting, and how much they have done. Always watch their faces, you can tell if they understand you or not. Also watch for that timid person who is afraid to ask, especially if you have someone in the class who is always talking or giving you advice! :x It seems that some classes have those people who know a lot or think they do and want to help teach or tell you a better way of doing things. I teach for one quilt shop and the owner always lets me know if I have one of those in the class! :) The main thing is to go into class over prepared and have samples and show them how to do each step. Good luck. Jan