Hey, GAH
I don't know, there isn't a WHOLE lot of stuff you need to buy.
If you're on a budget you may want to try cloth diapering. Cloth diapering has come a long way since the old days and it's really not so bad. There are some different brands that you can find on Mothering.com or just type in "cloth diapers" in google. You can buy a whole kit for about 70 dollars and most kits will last you up until about two years or beyond if your child isn't toilet trained by this time. Cloth diapers have definitely saved me a good chunk of money.
As far as clothing goes, you can go to your local Thrift Store or Goodwill. Down here in Florida at the birthing center I went to. The moms traded out baby clothes, clean cloth diapers, etc. A lot of moms were selling their old baby clothes for next to nothing, too.
Another thing might be a good sling or baby carrier. Both my kids loved being carried in a sling. As a matter of fact, my daughter still loves it (5 months) and it puts her right to sleep. I didn't buy anything fancy, just a plain black cotton sling when my son was born and it's still in great condition like I first bought it. Oh, a sling can range anywhere from 27 dollars (what I paid) to 100s maybe if you're looking for something fancy, but it's really not necessary.
Although I had a baby bed that was given to me by a friend, I decided to co-sleep with both of my children. If you're breastfeeding it's a lot easy to just slide baby into the crook of your arm and feed her when she's hungry. I actually think it's healthy to co-sleep with your baby, but I know there are conflicting opinions. So, I wont go there. I will say though, that you should chat with some parents who do co-sleep with their children. Another plus to co-sleeping is that you save 100-200 dollars on a "Made in China" crib.
I say don't use chemical shampoos or washes on your baby's skin. You baby has such delicate thin, skin that it will absorb things much faster than yours. Did you know most baby soaps contain formaldehyde and an array of other toxic chemicals? This includes name brands like Johnson and Johnson. I suggest learning to make your own baby wash. You can use rose petals, lavender, chamomile, cornstarch, etc. and you wont be putting toxic stuff on baby's skin. It's also fairly cheap to do this. A bag of rose petals cost me 2 dollars at my health food store. I can find you the recipe if you're interested. Oh, and I use coconut oil or shea butter on my kid's skin after their baths. Shea butter and coconut oil range from about 5-11 dollars for a jar, but they will last you a good while.
There's a lot to learn and if you're interested in finding out more just send me a message. I'm always happy to answer questions about different stuff pertaining to babies and child rearing. Good luck and congratulations on your baby!