Best tips are:
Eat 4 - 5 small meals a day.
Meal portions: Half of your plate should be veggies, or two big handfuls, but basically eat what you like. Quarter of it should be lean protein, about the size and thickness of your palm. , Quarter of it can be slow carbohydrates such as brown rice, lentils, beans, quinoa, amaranth, etc, but you can cut the slow carbs if you like.
Don't drink your calories. Drink water, tea, or coffee (Only one or two cups of coffee is recommended.) And don't add any milk or sugar to anything. Be sure to drink plenty of water, especially when active.
Eat plenty of vegetables, as colourful as you can. You can eat as many veggies as you like. They're very nutrient and anti-oxidant rich, which means anti-aging as well. The reason you can eat pretty much all you like is because it's mostly water. Examples: Broccoli, spinach, cauliflower, carrots (Maybe limit to 1 or 2), lettuce, kale, collard greens, cabbage, rutabaga, squash, bell peppers, etc. Limit potatoes, and other sweet veggies. Steaming is optimal, next is boiling, next is frying (Use unrefined extra virgin canola oil if possible, limit to 1 tablespoon or less)
Eat fruits, but make sure they're the right type. Apples and oranges are awesome. Anything with a peel, or citrusy. Berries are also awesome. Stay away from bananas, grapes, and dried fruits, due to fast carbs and sugars.
Have a small handful of healthy fats with a meal, if you like. Unsalted, raw nuts and seeds. Avocados (Be aware that one medium avocado is a small meal.) Avoid oils, but if cooking with oils, use healthy, non-refined, extra virgin oils.
Walk for at least 2 hours everyday. You can split the time up if you like. Walking around at work or school doesn't count. It has to be on your own time.
Eat whole, real foods. Read the ingredients on food that is processed. If it's got ingredients you don't understand, don't buy them. Period.
Cut out everything else. No refined sugar, no breads, no processed packaged foods. (Dark, wholegrain and wholewheat Breads can be good for you, but not optimal for weight loss, especially if problems with portion control.)
Extras: Spices are great, and add flavour. Again, limit oils, but spices will taste better if infused in oil for a time. Limit salt intake. For salads, use lemon juice and some spices for a nice pick me up.
As a side note, I like to drink lemon water before eating breakfast to help with digestion.
Example Meal Day:
Breakfast: A bowl of oatmeal, with berries on top and cinnamon. Small handful of nuts to garnish if desired.
Snack: Salad with cucumbers, lettuce, small handful of nuts, lean protein of some kind, lemon and spices. Have fun with it.
Lunch: Black beans and brown rice with lean protein of some type, tomato puree, cumin, basil, oregano, added water until favoured consistency. Add as many veggies as desired.
Snack: Apple with plate of carrots.
Dinner: Stir fry with baby corns, bean sprouts, quinoa or other type of grain or legume, few splashes of soy sauce, some spices.
Bam, done. You can even have a little snack before bed if you like.
Follow this advice strictly, and you will reap the benefits. Disclaimer: Meal plan was only an idea. Variety in eating is optimal.
If interested, I recommend this site for recipe ideas. If you're a meat eater, you can always sub for lean protein.
http://www.healthyeatingstartshere.com/
There are also other resources and plenty of food blogs.
http://fitnessista.com/
http://healthifulbalance.blogspot.de/2012/05/4-day-weekend-plans.html
http://blueberrysmiles.com/2012/05/15/mothers-day-eats-wiaw-20/
http://www.peasandcrayons.com/ (If you look at her ''What I Ate Wednesday'' post, there are links to others that show what they eat. They're pretty much all geared towards healthy eating and fitness.