Step 1 (I'll bet you haven't done it yet, but it's crucial): Find out how many calories a day you are REALLY consuming. I know, it varies, but log it for 7 days and average. If you don't know this, you're not starting off on the right note.

Step 2 - Account for workout burned calories

Step 3 - Aim for -200 to -500 calories per day while training. Again, you don't have to be super-anal about counting each and eveyr calorie - if you've done the 7 day food log, you should be able to cut out 1-2 items at dinner or snacks that will achieve it without math.