Aside from the big items, etc, that we are buying ourselves (dresser, crib, mattress), when should I start considering buying some items like clothes and stuff? In laws are buying us either the stroller or high chair. I'm not sure what my parents are getting (but MIL will probably corner my mother at Thanksgiving dinner this weekend and ask).
As of right now I literally have two onsies and that's it. That's all we have. My shower is November 23, so everyone says to wait until after that to buy the leftovers you need.
I still need to figure out what we are doing with baby in the bedroom as well.... tonight DH and I are re-arranging the master bedroom and cleaning it up so that I can measure and make a few plans.
I'd wait on clothes until after the shower (unless you feel like money will be extra tight around the holidays)- that still gives you a good month or two, and you are likely to get a lot of clothes/bibs/onesies/socks at the shower. Most people can't resist those adorable little outfits, even if they are also getting something else!
I forget, are you planning to do cloth or disposible diapers? You could start stocking up on those a little bit now.
It's been helpful for me to figure out early what our big purchases would be (carseat(s), crib, breast pump) and try to spread those out so we're not dropping a kajillion dollars at once. So this time around, we've bought all the carseats (had to get some new, narrower ones for the older kids so we could fit everyone in the car simultaneously), but are waiting till we pay that off before we go shop for a crib.
The most essential things you'll need when baby arrives are a carseat and somewhere for him/her to sleep (whether it is a crib or cosleeping or a bassinet or whatever). Other things are nice to have in place, but you can get by the first few days without. Many hospitals let you take home whatever diapers you didn't use, too.
Stuff like high chair and stroller can wait if necessary. Baby doesn't use high chair until s/he is sitting independently, usually- around 6 months.