Calorie Goal

It depends what you have put in your settings...you can lose, maintain or gain weight depending on which settings you choose. You can also select the rate at which you lose. Have a look on my blog http://harderbetter-fasterstronger.blogspot.com which has some calculations to find your ideal weight, Basal Metabolic Rate, Daily Caloric needs etc. to lose a lb of weight in a week (of ACTUAL BODY MASS, NOT WATER) You need to have a deficit of 3500 calories a week or 500 calories a day. Double that if you want to lose 2 lbs, so 1000 calorie deficit (from your daily caloric needs based upon your BMR and activity levels) per day or 7000calories a week... reverse it if you want to gain. Don't change your calories if you want to maintain (from the calculated Daily Caloric Needs...you might be over eating for your weight now! or under eating!)

When you filled in your profile, MFP gave you the option to choose between

Lose 2 lbs per week
Lose 1 lbs
Lose 1/2 lbs
Maintain
Gain

If you chose the right option, the calories goal given to you by MFP is what you should aim at.

This.
It's been so long since I've been in the settings part I'd forgotten about the gain and maintain bit.