workout suggestions
Okay, freestyle28, sorry it took me a couple days to get back to you. Here are a couple of suggestions for you:
If you're planning on getting started with lifting, I would stay away from machines entirely. What you want are free weight exercises, preferably exercises that involve your entire body. When you do lifts that work your whole body, the transfer of motion through your core is what will help with your abs. Obviously, sitting on a leg press or a chest press machine where the machine stabilizes your body for you will not require you to use your core, and so will not have any useful effect on your abs.
Some basic movements that you'll want to concentrate on are: squats, lunges, pushups, pullups, situps, leg lifts (for lower abs), planks, and almost any olympic lift, such as deadlifts, cleans, clean and presses, clean and jerks, split jerks, etc. You can also combine any two basic exercises to create a total body movement, such as lunges with bicep curls or squats with overhead shoulder presses. If you have the benefit of getting advice from a trainer at your gym, you can ask for help with your techniques.
Also, as a side note, you might consider checking into Pilates. You don't have to actually take a class, but it would be a good idea to research the techniques used to keep your core (and by extension, your abs) controlled during total body movements. It also helps with posture...and standing up straight is a sure-fire, immediate way to shrink your waistline.

In a nutshell (and I am a Pilates instructor as well), I will tell you that the trick to keeping your core tight is to do a Kegel--pull up on your pelvic floor as if you're trying to stop the flow of urine. Sounds goofy, but it tightens all the muscles of your core and protects and strengthens your spine while you do any exercise.
Finally, you mentioned running football fields. Fantastic! Here's a great workout that you can vary depending on how much time you have, how in shape you are, how hard you feel like working, etc. It is meant to be super high-intensity, so get ready to push yourself:
Starting at one end of the field, you're going to run suicide sprints. Basically, you run out to a yard line and back to the start, then the next yard line and back to the start, etc. Some example would be 0-10-0-20-0-30.....all the way out to 100 yards and back. Or 0-25-0-50-0-75-0-100. Or 0-20-0-40-0-60-0-80-0-100. Pick your own interval...like I said, it's very adaptable. You can stop when you get back from 100 yards, or you can work your way back down in the same intervals you used going up to 100.
Here's the kick, though. Instead of running consistently, you pick an exercise that you do every time you get back to the 0 line. Squats, pushups, situps, planks, lunges, pullups (if there's a bar nearby), jumping squats, burpees, mountain climbers, squat thrusts, or if you have a pair of dumbbells you don't mind carting around you can do any overhead lift.
An example might look like this:
Sprint to 20 and back
20 squats
Sprint to 40 and back
20 squats
Sprint to 60 and back
20 squats
Sprint to 80 and back
20 squats
Sprint to 100 and back
20 squats
Or this:
Sprint to 25 and back
10 pushups
Sprint to 50 and back
10 pushups
Sprint to 75 and back
10 pushups
Sprint to 100 and back
10 pushups
Sprint to 75 and back
10 pushups
Sprint to 50 and back
10 pushups
Sprint to 25 and back
10 pushups
It's infinitely variable, depending on the distances you choose to sprint, the type of strength exercise you choose, the number of reps you choose to do of that exercise, and whether you stop at 100 yards or choose to work your way back down.
Have fun!