Before reading this, I'm a certified personal trainer, not a dietician. To seek personal advice on nutrition you should consult with a nutritionalist. What I can do is provide guidelines to point you in the right direction. Look at the table below for recommended daily values for grains, vegetables, fruits, dairy, oils, meat and beans. Keep in mind that these values are recommended for a 2,000 calorie diet. If you eat more than this amount, you will be consuming more of every category essentially. This isn't necessarily a bad thing, as everyone has different caloric expendatures, depending on body size, composition, and activity level.
When concerned about losing weight, the primary goal is to burn more calories than you consume. That's the bottom line. The healthy way to do this is to restrict calories consumed while getting in essential nutrients and exercise. A pound of fat is 3500 calories, so a common approach would be to create a 500 calorie defecit each day. Cutting back your calories by 250 and exercising to burn 250 calories can accomplish this. A 250 calorie workout might take 15-30 minutes at moderate intensity. This approach should yield a loss of 1 pound per week.