A sophisticated, and in some ways easy, way to count calories is to use the free accounts at FitDay and have them figure your calories for you. There are lots of entries and they can also do custom foods.
Even though BFL doesn't call for calorie counting, I do it anyway. It helps me know where I want to be.
To determine how many calories you should be eating, you can figure your Base Metabolic Rate. There is a formula for this or you could just go to Hussman's site and let them figure it for you. You need to know your % body fat to figure it out, though.