Eat healthy! Simple as that. Cut calories, cut out junk foods, reduce processed foods, avoid saturated and trans fats - and sugary foods. Instead, eat nutrient dense foods: aim to eat 5 portions of fruit and veg per day - try whenever possible to eat fresh, local, in season, and even organic produce (within budgetary limits!). Vary your diet, especially the fruit and veg - try not to restrict yourself. Also (within your calorific allowance), consider some nuts and seeds - almonds might be a good choice. Eat some good fats - such as the nuts and seeds - or oils such as flax oil, extra virgin olive oil, walnut oil etc. Eat plenty of good lean protein - vegetable proteins, chicken and turkey white meat (not processed or fried), fish, some boiled eggs, reduced fat dairy products (not too much mind if you also want to lose weight).
Eating healthy nutritious foods and eating properly (ie. eating small and often) will help you lose weight as long as you are also controlling your total calorific intake. Combine it with exercise to fuel your metabolism, and you have the foundations of a top grade weightloss plan.