White sugar is will heat up a compost pile. 2.5 pounds would probably be enought for about a cubic yard of brown material, which would be a 3ftx3ftx3ft pile. Leaves make an excellent brown material and the best way is to layer the material. Put a thick layer of brown material making sure it is wet and then sprinkle on some sugar, molasses or cotton seed meal works real well. Then another layer of brown material and sprinkle on more sugar, ect. until you get your pile the desired depth.
An excellent website on composting is the Master Composter site at www.mastercomposter.com