The baby will own you. Nothing a baby does is on any kind of schedule. You spend days, weeks, even months trying to figure out some semblance of a pattern so you can accomplish even the slightest task. And just when you think you have it figured out, they hit a growth spurt and everything goes haywire all over again. Plan for never having a plan-- or a schedule-- ever again. Period.
When I finally surrendered all power to my child was when I learned not to plan for what usually happens, but to plan for anything that could possibly happen. The diaper bag is your only protection against certain baby-screaming doom, and should never be left behind. I don't care if you're only taking the baby with you to get the newspaper on the front porch, it's possible the baby may develop a sudden attack of the duckbilled-platypus-space-measles right as you realized you've locked yourself out, and you live on an island with no neighbors. Include in the diaper bag everything you'd need for an overnight stay in the middle of a frozen wasteland. Make sure to pack Venutian-English dictionaries, should you be abducted on your trip to the grocery store. Don't forget the antidote to the black plague because Yugoslavia just might resort to chemical warfare while you're browsing the sale racks at Kohl's. You just. don't. know.
People tell you to sleep when the baby sleeps. At first, silly little inexperienced me thought, "well this is the best time to get all the chores done!" No, no, no, no, no. Sleep when the baby sleeps. Sleep is precious. Sleep is now exponentially more important than sex, food, personal hygiene and money. You will come to a point when the baby hasn't stopped crying/feeding/pooping for 3 days straight and you haven't even shut your eyes for 2 seconds. At that point you will honestly consider selling a kidney in exchange for 1 good hour of sleep. I've often promised my children ponies, cars and all-you-can-eat ice cream buffets just to let me sleep for a few hours. Of course, they were just babies so I'll deny everything, should they somehow by baby voodoo remember what I said.
Your husband will most likely not believe everything you do in a day. Just because the baby spent 8 hours straight screaming to be fed and changed alternately every 30 seconds, doesn't mean that the second your husband walks through that door, she won't stop, smile and fall right to sleep, leaving him to wonder what you "really" did all day. Your goal here is to somehow find proof that your little sleeping angel actually transforms into a screaming hellspawn the second your husband leaves. Video taping a psychotic meltdown (the child's, not your own ;-)) is not beyond you at this point. Trust me, I've done it. Eventually, your husband will give up all hope of having sex before the children are in college, and just thank you for remembering to wash his socks every so often. The smarter husbands will eventually learn to take care of themselves, thus ensuring themselves not opening their lunch pail to a bag of pumped breastmilk and a baby sock. The genius husbands will figure out how to mask their selfish desires with a guise of helping you. Such as... say... sleeping on the couch so they don't get woken up 20 times by the baby-- er I mean sleeping on the couch because the teeny little 10lb baby needs his half of the California King sized bed in order to sleep better. My husband and the couch have become great friends this past 2 years!
"I don't know why they say "you have a baby." The baby has you." ~ Gallagher