Where To Begin?

Read the Announcements at the top of the message board threads. Here are a few more good ones:
http://community.myfitnesspal.com/en/discussion/10097870/the-really-blunt-list-of-things-to-consider-when-losing-weight/p1
http://community.myfitnesspal.com/en/discussion/10196160/scale-stress-syndrome/p1

Baby steps are key. Don't try to change your entire life overnight or you'll likely end up frustrated and overwhelmed. Start out by simply logging everything you eat. Every single thing. Logging everything makes it easier to see where you can make simple changes that have a big impact.

For greater accuracy with calorie counts, weigh solid foods using a kitchen scale and measure liquids that can't be weighed.

Don't "play" with the numbers, underestimate calories eaten or overestimate calories burned in exercise. You'd only be cheating yourself.

Eat the foods you like just meet your calorie goal. You don't need to cut anything out or eat specific things to lose weight. You'll be more successful if you don't feel like you're depriving yourself. On that note, don't do "cheat" days or cheat meals; you only cheat yourself. Many people who do this up negating the rest of the week's calorie deficit and struggle. If you're already eating the foods you like you won't need to "cheat", anyway.

Start strength training as soon as possible. In my opinion it's more important than doing cardio because it is much easier to maintain the muscle you already have than to build new muscle later. When we lose weight it is a combination of water, fat and muscle. If you're maintaining muscle then more of your loss will be from fat!

The measuring tape is a better tool than the bathroom scale for judging your progress. In addition to "Before" pictures, measure your chest, waist, hips, thighs and any other body part you want to track and start recording them in MFP now. When the scale isn't moving your body might still be shrinking especially if you're lifting weights.

Get yourself into the mindset that you're making a lifestyle change and its not something that you will eventually finish. Time-based goals for weight loss often lead to perceived "failure". Keep in mind that weight loss is not linear and you will lose pounds faster at the beginning than at the end.