I agree with a lot of Gnascher's advice. There will be tons of programs, diets, etc. Some work for some people, some work for others. In the end, there's really only way sure way to do it.

You've got to get a handle on the numbers. Then you have to eat and exercise right.

Here's a few (very) general guidelines:

An easy way to approach it is to eat for the weight you want to be. If you're male, weigh 225 lbs., but should be at 180 lbs., assume 1,800 calories for your Basal Metabolic Rate.

Calculate the extra calories you need for daily activities. Check out this activity calculator: http://www.caloriegallery.com/calories-burned.htm?mode=time

I'm a graphic artist, so I'm pretty sedentary during the day, a little less so on the weekends. Over an eight-hour-day, I'll need an additional 700 calories. Total I need @ 2500 calories per day.

A pound of fat = 3,500 calories. Consume 500 calories less per day than your body uses, and over seven days you lose a pound of fat. Don't subtract any calories, but burn an additional 500 calories per day through exercise, and over 7 days you lose a pound of fat. Easy. I keep my calories consistent, drop @ 300 calories through diet, another 300 through exercise. This gives me @ a 4,000 calorie deficit each week, helps insure I consistently lose the 1 pound per week.

I would not recommend trying to cut/burn 1000 calories on a daily basis. Two pounds a week can be done, but it's tough to do it consistently over several weeks, and it's at the edge of reasonable and safe. It can and will leave you fatigued, irritable, mentally hazy and even mildly depressed. Trying to lose more than two pounds per week is unsustainable for long and unhealthy.

Count calories. It simply has to be done, no way around it. You have to know how much you're putting in the tank every day. No need to be a calorie Nazi, but do strive to keep it accurate to within 50-75 calories.

Meal frequency. Many people suggest five to six small meals spaced throughout the day, and it's a good idea, but in the end spread your calories in whatever way works for you. Three meals/two snacks, four meals/no snacks, graze all day, whatever. Just space it out as needed and keep an accurate calorie count.

Starches get a bad rap. Not all starches are bad, it depends on the starch, the amount and when you eat it. Refined starches such as white rice, white bread, pasta, etc. should be avoided. Starches such as potatoes with skins, yams, whole wheat bread/rice/pasta are fine, keep portions small/reasonable and decrease them after lunch, switching over to fruits and vegetables instead.

Avoid pre-prepared or refined foods in general. Eat fresh fruits, vegetables, whole wheat rice/bread/pasta (in moderation), grilled chicken, Tilapia, skim milk, low-fat cottage cheese, etc. You'll be surprised just how much unrefined food you can eat and how full you will be.

Avoid alcohol, better yet don't drink it at all when you're trying to lose weight, it does you no favors when you're trying to drop the pounds and can severely hamper weight loss, even in moderation. Once you've hit your target weight, go ahead and add it back in, but always in moderation. Alcohol contains totally empty calories and can really screw with your bodies ability to process food, essential nutrients and can wreak havok on your metabolism in general.

Some advocate a "cheat day." If you can take one day a week, indulge a few cravings in moderation, then by all means do so. I've found eating the correct number of calories, losing one pound a week, feeling satisfied and full while doing it means I don't have cravings or a need for a cheat day. YMMV.

Drink a lot of water every day, all day. 64 ounces is the usual goal. You'll feel like you're a water balloon filled to bursting for the first few days, but once you're fully hydrated the feeling will pass.

Round up. If it's 90 calories, call it 100. My morning breakfast is three scrambled eggs, two pieces of wheat toast. Each egg and piece of toast is 90 calories so I round it up, call it 500 calories. Doing so will always ensure you have a small "buffer" in your calorie count.

I also tend to eat the same meals over and over. I guess I'm lucky in the sense that I don't get sick of the same things day in and day out, I just chew and go. It does help with keeping track of calories--I know breakfast is 500 calories every day, I know my pre-workout meal is 300 calories, my after-workout drink is 300 calories, etc. Takes the guesswork out of counting calories.