Losing The “Baby Weight” After 7 Years

I am a married mother of 2 beautiful girls, ages 7 and 5. I am 27 years old and ready to lose the weight I gained from my first child! I was young when I had my first child and never really had to watch what I ate. I was usually somewhat active. After having her, I started working a full time job where I sit at a desk ALL day! I am horrible with excersing and am going to try to add that into my daily routine. I have already started by parking as far away as possible and walking around the parking lot of my office building every afternoon. I am 5?8 and weigh about 192. Before I was pregnant I was around 140 and would LOVE to return to that weight. With the help of Roni and all the other people, I know I can do!