If you're pregnant and think you'd like to do IPT with your little one, then it's a really good idea to prepare. It's best to prepare:
1) Your house: A waterproof mattress cover is a great idea if you'll be co-sleeping, because accidents will happen, (and even if you never have a miss in the bed, chances are, your breasts will probably leak). Over at tribalbaby.org, Charndra describes how she sewed a blanket to a waterproof tablecloth to put under the baby in the bed. I haven't tried this (it's one of those things I keep putting off, and looking back, I wish I'd at least tried it, because I really hate washing the sheets after a miss. (This doesn't happen too often though.)
Definitely get a potty, even if you plan on using the sink. I recommend the Baby Bjorn Little Potty style potties, but basically the best thing is to have one with a nice stable surface, with a comfortable seat that conforms to your baby's shape.
Planning out where you want to practice IPT before the baby comes is a great idea. What worked for us was the bathroom sink for the first several months. We set up the station with plenty of wipes, toilet paper, extra diapers, and pins (if needed). Try to decide now whether you'll use cloth or disposable diapers. With IPT, you'll probably have quicker success with cloth, since your baby will stay more aware of when she has a miss. Cloth diapers nowadays are just as easy to use as disposables, like with the BumGenius 3.0s. The only difference is the added laundry, which doesn't mean too much extra work, since with IPT, your baby won't be soiling nearly as many diapers.
If you don't use the sink, I'd recommend placing the potty in a place where the baby can see herself in the mirror. They love it! (For out and about, The Potty-On-The-Go (you can look at it in my Amazon Store) was absolutely essential for us.)
2) Your family: Let your husband, other children, and the baby's grandparents know that you're planning on doing IPT. It's common at first for people to be intimidated by the idea of potty training a tiny baby, but once they know more about it, they usually get a kick out of it. Let them know they can help out if they feel comfortable with the idea.
3) Yourself: Read as much as you can about IPT. Forewarned is forearmed, so the saying goes. Be ready to give an answer when someone asks if IPT could be detrimental to a baby. Having knowledge about how common this is throughout the rest of the world makes it so much easier to deal with people. Brace yourself for the occasional (rare might be a better word) criticism. Prepare yourself for criticism anyway, because no matter how you choose to parent your child, someone will always criticize your technique, whether you spank or not, or whether you breastfeed or not, or whether you potty train your infant or not. :)
I've tried to write about everything IPT related that I can think of on this site. I've also included links to other IPT websites, and links to books and other IPT products that I've found to be useful.
As always, feel free to email me with any questions!