Exercise

well, from my experience, this is what I did:

Cut out all the junk. Soda does not exist to me. And I cut out juice. I pretty much only drink water.

Secondly, I counted calories.
I made sure I was meeting my daily requirements for vit c, calcium, fiber, folic acid, iron, etc to make sure I was eating healthy and getting all the vitamins I needed.

Thirdly, I cut any boxed foods I would buy. Mac n cheese, instant anything, etc.

Fourthly, I cut out the foods that were high in sodium.

Next, I exercised 5 days a week 1-2 hours a day.

What I did was calculated how many calories my body burned all on its own, without exercise. I then subtracted 150 calories from that number and that was going to be the number of calories I ate everyday. Then I added exercise on top of that, burning even more calories.

So I was never consuming more calories than I was burning.
I ate 6 times a day.
I would eat a breakfast of about 200-300 calories
Snacks in between each meal that ranged from 80-100 calories
Lunch that equaled between 300-400 calories
Dinner that was about 400-500 calories.
*in between meals I drank water to keep my hunger at bay. However, after about a week, your body adjusts and you won't find yourself hungry! BUT, if you're late for your snack or meal, your body will respond immediately and be really hungry! (I ate every 2 hrs). So if you know you're going to have to be out running around, plan meals and snack that you can take with you with ease. Just like you have to feed your LO, you need to do the same for yourself.*

When I exercised, I did light strength training, however, I've read a lot of studies that show that a good strength training routine helps you to lose weight faster. But I only did strength training for about 20 mins of my workout. I got bored. In my opinion, free weights are the best route! You get results super fast and you don't have to spend as much time as you do on machines.
As far as cardio goes, I am particularly fond of the bicycle. It slims your legs and hips down so fast! It's amazing. And then the machine I spent the most time on was the eliptical. Love that machines. You can burn a lot of calories on that.

On the days I didn't go to the gym, I ran about a mile. I'm not fond of running. It is definitely not my favorite thing to do!

In everyday things, I opted for the stairs instead of the elevator or escalator. I did a lot of walking. My grocery store was about 3 blocks away from me, so i'd walk to the grocery store instead of driving. I'd break up my grocery list into smaller lists so I was only picking up a few things at a time, and walking back to the store about 2 times a week.

I think the key is planning. And then you can lose weight in a safe and healthy manner.

Good luck!
If you try any of these things, let me know how it works for you!