You might find this chart a big help until you understand the whole carb counting diet. The glycemic index is determined by how long your body will take to burn the different food, eating foods from the lower glycemic levels help lower your blood sugars. You still count the carbs you eat but at the same time make the carbs you eat at an even rate to maintain yourself at the best levels.
This explains glycemic index of foods:
http://en.wikipedia.org/wiki/Glycemic_index
This is the Glycemic Chart:
http://www.lipid.org/education/cours...ycemicDiet.pdf