Many products have the amount of carbs on the nutrional information that is on the package. Many times it even breaks it down to the percentage of how much that particular food fulfills for that day. You can go on to different sites on the web to see what the nutritional makeup is of food that has no info on the packaging like meats and veggies. I can't remember off hand how many grams of carbs you should be getting in a day, but I'm sure that is easy enough to find out, as well.

Measure your food, cups/weight and use something like fitday.com to help calculate them.

Or pickup a copy of Corinne Netzer's Complete Food Counts. Great resource. Amazon info at

http://www.amazon.com/Complete-Book-Food-Counts-7th/dp/0440241235/ref=sr_1_1/105-4202276-5578814?ie=UTF8&s=books&qid=1192498882&sr=8-1

Ooh - almost forgot - Remember to check the glycemic index for carbs. Lower glycemic values are better if fat loss is your goal. Netzer's book won't help you wtih that (unless the new edition does) - fortunately several sites exist that let you look up that info online.

For any diet that requires control over the intake of carbohydrates, it is important to understand what net carb is, and how to determine it from a food label. Net carb generally refers to the amount of carbohydrates in a food serving that have significant impact on blood sugar level.
The traditional way to determine net carb is to subtract grams of fiber, and other carbs that have negligable impact on blood sugar (such as glycerine, and sugar alcohols) from the total carb count.

If fiber is listed on the nutrition label, just subtract it from total carbohydrate count. Sugar alcohols may be seen on nutrition labels as (these are most common):

sugar alcohol or polyols
maltitol
xylitol
erythritol
sorbitol
Therefore, if you see any of these on the nutrition label, you may as a general rule subtract them from total carbohydrates as well.

Here is an example of calculating net carb when both fiber and sugar alcohols are present:

Nutritional Information
Serving Size 100g
Energy 80 Cal
Protein 4 g
Carbohydrate 12 g
Fiber 4 g
Maltitol 5 g
Fat 2g

In this example, net carb count is just 3 g (12 g carbs - 4 g fiber - 5 g sugar alcohol).

Now, having said this, the blood sugar response for some may be higher than others when it comes to sugar alcohols. Some argue sugar alcohols should not be completely disregarded in net carb count, especially if you are diabetic. Some low carb diets, such as Dr. Poon's Metabolic Diet, puts limits on how much sugar alcohols may be consumed per serving. For others, you might simply treat products sweetened with sugar alcohols as simply that - treats that may be consumed on occasion only. Your individual experience with sugar alcohols may also differ depending on the type (i.e. Maltitol vs. Xylitol).