How to lose body fat?

I am a 23 yr old male. I am trying to lose body fat or whatever, not necesarily weight but just the "flubber" I have on my stomach. I weighed around 130 lb when I found out my wife was pregnant. During the pregnancy I gained about 50 lb, so I weigh 185 lb right now. I just got this blubber on my stomach, hangs over my pants now looking like I'm pregnant. How can I lose it? I don't exercise but I'm starting this construction job on a government arsenal so I know I will get exercise just working. Like what kind of diet, etc should I use to lose this extra fat to just have a flat stomach?