Watch both of these:
http://www.dailymotion.com/video/xz2...cise_lifestyle
http://www.dailymotion.com/video/xvd...-hd_shortfilms
You'll quickly realise there is a lot of truth in the phrase 'your body is built in the kitchen, its only polished in the gym'. You need to get your diet in order to drop the weight and keep it off. Exercise is to improve your fitness and improve your cardiovascular health.
Ignore advice about avoiding carbs, fructose, etc. What matters most is reducing *calories*. How you reduce those calories is largely up to you. You may decide to cut back on the carbs, you may cut back on the fat. Whichever is a matter of personal preference. The goal is a diet that you are happy with. If it feels like punishment, you wont stick with it.
Get a calorie-tracking app, if only so you actually start to learn the relationship between calories, types of food, and how much you need. You wont need this forever, just until you get a feel for how much food you actually need versus how much you think you need.