A food diary will help you figure out how many calories you consume every day.
You'll need a three-ring binder, a three-hole paper puncher, paper and your printer. I've got the food diary pages you need to keep track of your diet.
You also need to know how to measure your portion sizes. A kitchen scale, measuring cups and spoons will come in handy.
Finally, you'll need a nutrition database to find all the nutrition information for foods you eat that don't have Nutrition Facts Labels. My favorite is the United States Department of Agriculture National Nutrient Database.