Long before becoming pregnant with my first, I decided that I would be a stay at home mom. As it turned out, before giving birth, I was doing regular freelance work from home. After my oldest son was born, I took a short break for the first couple of months and then slowly picked up more freelance work. I later learned that working from home with a newborn is one of the easiest scenarios--in comparison to a toddler or preschooler, whew! Four years later, I maintain a part-time work from home/part-time stay at home mom schedule. It's hectic at times, but I am so happy with my set up. I truly feel that, for me, it's the best of both worlds. I have a ton of respect for full-time working moms, who are pulled in so many directions, and full-time stay at home moms who are "on" with their kids for several hours a day (kids are wonderful, but they're hard work!).
You might already know exactly what you want to do when baby comes, but if you're a mom-to-be that's on the fence about working or staying at home, read up, talk to other moms and do a little pre-baby soul-searching. Of course, I realize that for some, not working is not an option. If you're a mom who needs to work but yearns to stay at home, consider asking your employer if there is any flexibility in your work schedule or perhaps search for other opportunities that are more baby-at-home friendly.
Here are a few good reads that may help along your journey.