I agree with the folks above who said vegetarian lifestyle alone won't pull you through. I have learned over the past seven or so years a lot about food, portions, fat, calories, and food density. Before my 12 year old's birth, I was floored by the idea a co-worker shared with me: after a super big lunch she was going to eat just a salad for dinner to compensate for the calories. I've come a long way. ;-)
I slowly lost weight since my 9 year old's birth by making item by item eliminations. First, I had to eliminate certain basic veggies because it caused colic so I had to learn new veggies. Then, I gave up meat mostly because I didn't ever care about meat--just the sauces. So I could cover tofu dogs, garden burgers, etc with all the crap I loved and had no problems. By that time, I'd lost 20 pounds because I eliminated a lot of caloric meat/fat for smaller portions and reduced fat/calories.
Next, I gave up dairy products in solidarity to my son's 2-year lactose intolerance and learned it is possible to live without dairy (I've added it back in, in moderation over the past year). I lost another 15 pounds with that one.
I slowly increased walking and aerobics until I made it down to a fluctuating 180-190.
As a recommendation, I really love Barbara Rolls' Volumetrics. It complements my vegetarian meals. Instead of noodles and a spicy yummy stir fry, I substitute bean sprouts. The philosophy is to eat water rich foods like bean sprouts, water mellon, grapes, etc. It also suggests eating every 3-4 hours to keep the stomach functioning properly and avoid hunger pains. I really love the whole thing. I think it's great for maintaining, too.