Perhaps you need to read the chapters on the science behind the diet, as well as concentrating on just the carb count of everything in sight.

The Acceptable Foods List is what you go by initially. It is not only based on lower carb choices, but also low glycemic load (how they effect your blood sugar levels) products.

I use two different sources for looking up carb counts:

Nutrition Data's Nutrition Facts

and

USDA (has even a downloadable version for your home computer)