I've seen/experienced more dog bites from crazy little dogs than I have pits or big dogs. My son got bitten by a nutso Jack Russell terrier (we were standing in our own driveway, minding our own business, and this little thing ran across the street, leaped up, and chomped my son on the cheek). The difference is that the Jack Russell was so little, that it barely broke the skin -- no one (except me and my crying son) made an issue of it. The owners pooh poohed it, like it was "normal", acceptable behavior.
Had my Boxerbull done the same thing, people would have been screaming to put it down. My dog is over 90 lbs, and a nip or bite, even in play, can do some serious damage. It's a bigger, i.e. scarier, dog, and the myths and "dangerous" reputation have been running wild for a long time.
Best thing I've found: Train your pit to be the most well behaved, polite mofo on the block. Lot's of interaction with other dogs and people, and proactive control while in public. I try to NEVER let my pit mix look like a "stereotype". I am also pretty vocal with telling people, "That's actually NOT true about blah blah blah.....(insert pitbull myth here)."
I'm kind of funny about not completely trusting ANY dog 100%, regardless of size or breed (even my own dogs, who are extremely gentle and sweet), and stating that to other people. Why in the hell would I let someone's toddler in my dog's face? I have some pretty nice dogs, but it's a risk I'm not willing to take, for the kid, or my dog.
Enjoy your new "baby".