Diet works, and exercise makes it work faster. Supplements can help also, but not on their won.
Diet -
Calculate your maintenance calories required. A simple tool to use: (
http://www.freedieting.com/tools/calorie_calculator.htm )
Determine your macronutrient input: Example using 2500 cal/day
Fat: 2500 cal/day x 25% = 625 cal. Fat is 9 cal/gram, so you fat allowance is 69.5 grams.
Split remaining calories 70%/30% between protein and carbs: 2500-625 = 1875 cals x 0.7 = 1313 cals protein
and 563 cals carbs. Get your card from greeen, leafy and fibrous vegetables, stay away from sugars and fast starches. Read about keeping your glycemic index low and eat low glycemic index carbs:
http://www.health.harvard.edu/healthbeat/a-good-guide-to-good-carbs-the-glycemic-index Exercise 15-30 minutes at least 3 times per week. Screw the gym. Just do something that makes you a bit our of breath and sweaty for that length of time. You don't need special equipment.
After 1 week, drop your calories by 100 cal/day. Each week thereafter, drop your calories by an additional 100 cals per day until you are 500 cals/day below maintenance. Recalculate frequently as you lose weight.
A simple tip: Buy a cheap set of body fat calipers at GNC, and target reduction in % body fat instead of targeting weight. Many people get discouraged when they seem to stop losing weight, but the body is simply rearranging nutrients between body compartments - a process called recompositioning.
A good multi-vitamin is a good idea for a new diet starter, but a daily green tea capsule high in EGCG will help with weight loss. If you have or may have metabolic syndrome, 1,000mg of cinnamon daily will also help to control glycemic spikes and partition food towards lean mass rather than fat. 1200 mg or triple fish oil may also help. Their are other (maybe better) supplements, but they only work for certain people under certain conditions.
When you have some diet and exercise discipline built up, techniques like carb-cycling can make weight drop off very rapidly.
Good luck. Happy to help if you PM me.