This probably doesn't warrant an entire blog post, but I thought of it due to an interaction on Twitter.
So, you want to lose weight, and you know in order to do that, you need a calorie deficit.
There are countless calorie calculators online and smartphone apps to help you with this.
Anytime you restrict calories from your diet, you are upsetting your body. Your brain especially, is used to getting a certain amount of energy. When you restrict calories, you may find that you are moody, and can't think clearly. If you find yourself like this, for more than a few days, there is a chance you have cut too many calories initially.
So, armed with this information, you find a site/app that you want to use, and put in your height and weight and it gives you some numbers. Great. So, you should (depending on the app) get numbers for Weight loss and numbers for maintenance.
One thing that really worked for me, was to set small target weight goals, say like 20lbs lighter than wherever I was a point in time. Use a calorie calculator to find the amount of calories a person your height, and that weight should eat to maintain their weight. Eat that amount. What you will find, is that (perhaps more slowly than you'd like), you will eventually reach that weight. Once you do, you will have adjusted to eating that amount. You can then set another incremental goal and repeat the process.
This can really help in avoiding the yo-yo effect, and can make you happier (and those around you happier) as you reach your goals.