A couple thoughts on the actual mechanics of raising babies. First, breast feed. It's actually amazing that anybody would voluntarily put themselves through the hassle of dealing with bottles when there's this always-on supply ready to go. It's also the universal fix button. Plane's landing, baby starts crying? Stick a boob in his mouth. Sorted.
Cloth diapers vs. disposables. Cloth diapers are pretty impressive these days. They generally work, don't smell too bad, clean up fine, and are probably even cheaper in the long run. But here's the thing. Disposable diapers are made out of pure magic. You really have to see it to believe it. You know why we don't have Mars bases and hoverboards? Because every genius mind in the last 40 years has seemingly been working around the clock to make a single pair of Huggies Active Fit hold 15 gallons of urine without leaking. You can leave your kid in one for weeks on end if you feel like it. Honestly, it's the single greatest invention of all time, and they're like $0.25 per poop. Sorry cloth. Sorry environment. Disposables rule.
Good luck!
We are missing some facts here that would help give guidance.
What does mom do now, does she plan on doing after baby is born?
You haven't mentioned your role at the startup, how many folks are involved or working with/for you, and when you think you are going to launch, and in what general sector (b2b, SAS be vague but give us some clues)
There is one more key factor, and thats do you have other family near by you... this can be a blessing and a curse, but help is help and take it where you can get it.
General parenting stuff:
Im sure you know other folks who have kids, you need to start asking them about the things they learned that could have made the process easier. Your going to hear lots of stuff take it all to heart and listen its going to sound a lot like...
Tips like making the bed with a mattress protector, a sheet, another mattress protector, another sheet, another mattress protector... cause at 3am you don't want to have to re-make bed due to an accident, and pulling off the wet sheets lets you go back to sleep quickly.
Learn to nap now your going to need them
Buy this, follow its advice http://www.amazon.com/Twelve-Hours-Sleep-Weeks-Step/dp/05259...
sleep will make or break you, sleep will be the thing you long for.
Find out how to cook things that are fast, easy, healthy and don't destroy the kitchen.
Realize that any aversion you have to bodily fluids are going to disappear quickly, as a parent pretty much nothing grosses me out any more.
Plan on having at least 3 months after birth where your a total MESS. You might have good days in there but don't count on having them or being able to plan them.
Bottle feeding has advantages, one of you can get a good nights sleep every now and again. Also feeding time is reading time, I learned more bottle feeding my kids then I have since.
Find playgroups and peer groups early. This is mostly going to be you walking your kids around with other parents in the early days, but other moms and dads with the same tired expressions, strollers and diaper bags are a good reminder that you aren't alone!
I have zero practical advice to give you but I can relate as I am in the exact same position. Stressing out to get as much done prior to 11/30.
The one thing that I keep hearing about is the yo-yo feeling of guilt. Guilt that you aren't doing enough at work, guilt that you aren't doing enough at home. Ultimately, I am trying to get myself in the right mindset to be able to look past those feelings and realize I am doing the best that I can and that will have to be good enough.