Hey Dan, Once you apply a fog to the light the blue cone should show up automatically. You should notice the cone gets larger with a blue cone around it. In regards to decay. This allows you to control when you want your light to start and end. To control the decays you can do it manually in the attrubute editor under light effects or with the cone selected and in manipulator tool mode by clicking on the blue follow through tab on the manipulator you can click on this till you get the decay regions to display. You can then control them by middle mouse clicking on each region. Curve intensity is also good to use. You can create one and than edit it in the Graph Editor. This tells maya what intensity you want the spotlight at different regions. I hope this helps.