Nine or ten months seems like a lifetime at the beginning of your pregnancy, but as that due date approaches, many mothers realize they suddenly have little or no time to get things done! They start thinking about how quickly those months actually passed, and how quickly baby will actually be here. This is when the panic sets in.
No need to panic! There are very few things you actually need before baby comes. Baby's needs are very basic, and they get many of those needs met by mom. When babies first come home, their basic needs are food, diapers, love, and a place to sleep. Love is completely free, as is food if you breast feed. For now, we'll just scratch love off the list, as it can be assumed that it's already set up for baby.
For baby's living space, consider where you want your precious little one to be when they're not with you. Some mothers co-sleep, some room in, and others put baby in another room from the beginning. There is no one correct option, so just go with what you think you'd prefer. If you will not be co-sleeping, choose a crib, bassinet, cradle or whatever baby will be sleeping in and set it up where you can easily get to it. Don't place their sleeping surface near a window, vent or heater, as this isn't safe. Also, keep it away from anything that might be hanging down into it or near it, such as curtains.
All you need in the crib is a mattress and crib sheet. Bumpers, blankets and other parts of a layette set are not only unnecessary, but dangerous! If you truly feel the need to have bumpers, invest in mesh crib bumpers, which are much safer for babies. Sleep sacks are a fantastic and much safer alternative to blankets, and can be found at a wide variety of stores. Mind you, these are not necessities, simply alternatives if you feel you need them.
As far as diapers, the hospital will provide diapers while you're there, so don't stress about having them in advance. There's plenty of time to run to the store once baby is here, though diapers are fairly pricey, so stocking up in advance doesn't hurt; it simply isn't vital. It's not quite as easy to stock up on cloth diapers at the last minute, unless you're in an area that is very friendly to cloth diapering, but the basics can often be found at a Target, Walmart or similar store. Wipes or clean cloths are also important accessories, especially when baby first comes home and has meconium diapers. You will need something gentle that is either already wetted or that you can get wet. Otherwise, you will be dealing with a sore, raw bottom. For those preferring not to use store-bought wipes, flannel and soft cotton are excellent options for cloth wipes.
If you will be breast feeding, you don't have to worry about stocking up on food, but if you'll be formula feeding, baby will need bottles, nipples, and formula. You do not need a sanitizer unless you'd prefer one. For your ease, try to have the bottles and formula somewhere easy to reach. if you are up in the middle of the night, you will not want to be tossing things out of a closet in order to find that elusive bottle!
Other than that, try to keep your home tidy, and your floor free of debris. Though baby won't be crawling around on the floor any time soon, you will be carrying your new little one around everywhere and will still have a bit of a belly at first, so you don't want to have anything on the floor to trip over. This is also true for the area around baby's sleeping space; you'll be making the trek from your bed to theirs in the middle of the night when you are still about ninety percent asleep, so minimize your risks.
Everything else is just window dressing and convenience. You can take care of anything else after baby is here, so don't go crazy before baby arrives. You'll figure out what you need as you go, which will save you considerable money. Many people spend a fortune on a bunch of things that sound good at the time, but that they end up not actually needing once baby is in the picture. Baby only cares about comfort, safety and food, so don't knock yourself out trying to buy all the newest, best things when there's no need. Have fun being a new parent instead!