Three keys to losing weight are:
1. Counting calories
2. Determining your BMR (Basal Metabolic Rate)
3. Eating frequently (4 or 5 times a day) ... and drinking lots of water.
To get an accurate reading for your BMR you will need to calculate your body fat percentage. The easiest and fairly accurate way is to use on of those plastic calipers. This is what I use
http://www.amazon.com/Accu-Measure-Fitness-3000-Personal-Tester/dp/B000G7YW74/ref=sr_1_1?ie=UTF8&qid=1368200799&sr=8-1&keywords=fat+measuring+calipers
Once you get the body fat percentage, subtract the percentage in pounds from your total body weight. That will give you your lean mass. You will need to convert the lean mass figure into kilos based on the calculation I have.
Your BMR = 370 + (21.6 X lean mass in kilos) = number of calories your body consumes by just living and breathing.
Next you multiply the BMR by an activity factor to get your TDEE (total daily expenditure level).
Sedentary = BMR X 1.2
Lightly Active (workout 1-3 days a week) = BMR X 1.375
Mod Active (workout 3-4 days a week) = BMR X 1.55
Very Active (workout 6-7 days a week) = BMR X 1.75
Ext Acitve (hard daily workouts, heavy sports) BMR X 1.9
This gives you the number of calories your body will need to maintain your weight. To lose weight you need to be in caloric deficit. There are 3500 calories in a lb of fat. If you have been training and are only 20 or so lbs over your target weight, I'd suggest focusing on losing only a couple of lbs a week. Thats 7000 calories or 1000 a day.
So lets say your TDEE is 3000 calories a day, then you would cut that down to 2000.
Once you know the target number of calories, then you spread that out over 4 or 5 meals a day. Ideally eating every 3 or 4 hours. Breakfast being the most calories of the day and the last meal of the day being the least. Eating more frequent, smaller meals keeps your metabolism going and never leaves you feeling hungry. Also drink lots and lots of water. For a TDEE of 3000 you should be drinking 100-149 oz of water - daily.
What you should eat kinda depends on your body makeup. Everyone processes food differently. A good starting point is 40/40/20. Each meal consisting of 40% protein, 40% carbs and 20% fat. And there are good carbs and bad carbs. Good fat and bad fat.
So, in a nutshell, count your calories, figure out your TDEE, eat many small meals a day, and drink lots of water.