Fat burners, like any other supplement, only work if you have a clean diet and a good workout program. If you aren't eating right, or working out, fat burners won't do anything for you. Neither will any other supplement. Remember, a supplement is supposed to enhance a good diet and workout program, not take the place of either one.
I look at it like this. I'll use a point system. Diet gets 50 points. Workout program gets 50 points. If I maximize both of them, I'm working at 100%. When I'm at 100%, the right combination of supplements can be worth an extra 20 or so points. So now I'm working at 120%, which is really good.
Now lets say my diet is only getting me 40 points, meaning I'm lacking in some area of my diet. And my workout program is only 40 points, so I'm not working out my hardest. I'm only getting 80 points. So those same exact supplements that got me 20 extra point before may only be worth 5 points now, because I'm lacking in some important areas. If I'm only working at 50%, meaning that I'm barely working out, and I'm only eating a little better, those same supplements aren't going to be worth any points.
I hope that makes sense. If you workout hard, and consistant, and you have a good diet, fat burners, and supplements like whey protein and creatine, will work great. If you eat like crap, or don't workout hard, you'll be wasting your money.
Now about fat burners, I've used them and gotten good results, especailly ephedra. That stuff has a kick. It's hard to find, but you can still get it. But be very careful when you use it. I only used it before I went running. The lable says take it twice a day. But I only took it once, before I ran, which was 2-3 times a week. So I wasn't taking much of the stuff. The people who had problems with it were people who took too much of the stuff. These newer fat burners don't have the same kick, but they still work well.
For your diet and workout programs, I suggest you read Muscle & Fitness. It's a body building magazine that geared towards the everyday person. Flex, Musclemag and Ironman are geared toward the muslce heads who want to be 250 lbs with 6% body fat. I don't think any of us are looking for that look. Muscle & Fitness will diagram a workout and diet program for you, and it will teach you how to be your own personal trainer.
I hope that helps, and good luck.