This is what worked for me...

It's just some simple math; you need to burn 3500 calories more than you eat to lose 1 pound of fat. For 30 pounds, that's 105,000 calories which seems like a crazy number but you get 182 days to do it, so you need to average eating 577 calories less than you burn. For easier math and because it is more common to accidentally go a little over than under, make it 600.

Enter your stats to see how much you need to maintain:
Calorie Calculator

Set a daily calorie goal 600 below that. That was all really easy.

Now comes the hard part...
Join mfp (MyFitnessPal) or another site like it that has a phone app. I used mfp. Actually that part was easy too. Okay the actual hard part...

Log every single thing you eat every single day; no exceptions. The first few days, you don't even need to limit yourself; just eat like normal but record it all so you know what you are working with and can make decisions about what to limit.

Adjust your eating habits to the goal you set and stick to it. If it is too hard, adjust it and reset your expectations about how long is reasonable.

After you lose the weight, go back to the calculator and enter the new figures in and compute how much you burn. This is your new calorie limit if you don't want to gain it back.

Don't deny yourself foods; make them fit by trading off and having a light meal or two at other times so you can enjoy that piece of pumpkin pie or whatever. You cannot lose the weight and keep it off if you go right back to old habits.

The gym is a great idea; getting in shape while you are losing weight helps with motivation and gives you a few extra calories you can add to your daily goal on gym days. Just be careful not to overestimate how much you burn. The machines lie; it's hard work to burn 400 calories an hour. you lose the weight in the kitchen.