Any good suggestions on introducing my new baby to my dogs?

[LilabellHoney]

I am 14 weeks pregnant with my first child. I live with my boyfriend and out 3 wonderful pit bulls in a house we bought 2 years ago. I love my dogs, they are absolutely wonderful and I would never ever give any of them up. Right now they are used to my 14 month old nephew and my boyfriends 3 yr old nephew. They hug the dogs, pet them, give them treats. The worst the dogs have done is jump up because they are too excited or run away of the kids are being too rough. We have plenty of time to prepare my dogs for the baby, and want to make sure the first introduction is done correctly. Has anyone had this experience before? I know you are supposed to start by introducing smells of diapers and things like that but outside of that I really know very little. Any info would help or any books anyone can recommend. Thanks! And just to make it clear getting rid of the dogs is NOT and never will be an option so those of you with bias against pit bulls need not answer. Ill just report your answer and it will be removed so it's not worth your time.
To help answer the question a little background on their training: in general my dogs are well behaved, i walk two off them off leash most of the time and keep the 6 month old on leash because she is still learning. They listen well and will not approch another person or animal unless i give them the ok when they are off leash. They tend to get more territorial when on a leash. One of them doesn't do so well with other dogs but all 3 are fine with people. They get a walk every other day and when i exercise them, they just come home pass out and could care less about anything else for the rest of the day. they are protective of my family, but not aggressive. I can tell in their bark if it is a stranger or someone I Know at the front door. They are all rescues and the 6 yr old who ive had the longest was a severe abuse case. Still he is not aggressive with people, if some one he doesn't know is around, he will just leave the room. He does love kids though, especially babies. When my neph