Hi G.-
Congratulations!!
For clothes I'd recommend investing in just a couple of staples like black pants, jeans, that sort of thing. I did pretty well with non-maternity clothes that I knew I could wear afterwards- there are a lot of styles with empire waists, or stretchy ribbed that I was able to wear during and after pregnancy to get more bang for the buck. I also sent the word out and got hand me downs from friends. Oh- if you plan to nurse keep that in mind when you buy your clothes. I didn't lose my baby weight for a few months so I was actually wearing some of my maternity clothes afterwards, but needed to be able to nurse in them. So look for low necklines or button downs, even nursing tanks that you can wear while pregnant, or other things you'll be able to access your breasts from. This will help keep you from having to buy additional clothes just for nursing.
As far as baby stuff goes, I recommend the book "Baby Bargains" (we have it at our local library otherwise it is $15) which really helps you figure out what you don't need. For example, we didn't need the expensive crib! (Pack and play would have been fine if not as cute). And as for strollers, we didn't even get one until she was 6 months old, and it turns out she actually is fine in the $20 umbrella stroller we bought on vacation! Finally, see if you can borrow stuff instead of buy. You use it for such a short time. We borrowed a bassinet and glider. Wish we had borrowed the swing- we paid so much for it and she didn't like it at all!
Oh- take lots of pictures of your belly (with and without clothes) and include the date and measurements- I wish I had more of those.
Have fun with it! It's such a precious time.