I've been doing a combination of p90x and insanity. Insanity for the cardio workouts and p90x for the muscle building. Thus far, I have lost 65 lbs since June. As for a diet, eat 5-6 times a day (Breakfast, snack, Lunch, snack, Dinner, snack); spread the meals out by 2 hours. Keep the meals smaller too. Also make sure to cut yourself off from fast food and soda, if you still eat/drink them; having them once in a long while won't kill you though. And the rest is basically common knowledge, change snacks from potato chips or what ever to veggies and fruits, use whole wheat bread with sammiches, nuts are good too, and so on. Most of the info you can easily find online for free. You'll also want an after workout meal, something with protein, so you could make a tuna sammich/omelet with some vegetables and fruits, and for a drink you could have a whey protein shake or even chocolate milk. If you're doing cardio you'll want to eat carbohydrates an hour or two before the workout, and if you're weight lifting you want to eat carbohydrates and protein previous to workout. Minimize fatty food all day errday. That's pretty much everything I have done to lose my weight and build muscles. Make sure to drink a lot of water and it really helps to find an inspiration to lose weight. My family is eating healthier because of me, my dad has stopped smoking, and my mom has started walking around the block during her breaks at work. You can affect others just through what you do. Keep up the workouts and you'll be dropping weight in no time.
Edit: All of this cost no more money than I spent previously. Just change what you're buying. I'm sure, you being an internet user, you can find a way to get p90x and insanity online. Use all of your resources
. You can do it, bro.