Congratulations on your new baby boy! Keep in mind that whatever healthy lifestyle choices you make for yourself, will influence the lifestyle of your little one. So it's a great time to make some changes, you might as well since the rest of your life has been tossed end over end eh?
You mention that you are REALLY overweight. I don't know exactly how many pounds you want to lose, but I would like to invite you to check out the 100+ threads, even if you have less or more than that to lose. There is one for "Ladies only" and a "unisex" version. They are both great spots to check out, especially for those of us in it for the long haul.
Starting weight: 244.6 lbs. 10/01/09
Pounds lost: 80.6 lbs
Current weight: 164 lbs
Goal weight: 120 lbs
Weight to go: 44 lbs
Goal Date: 1/1/13