Congrats! And sorry the dad is giving you problems, guess it's better to find out what he's like sooner rather than later though. I hope his mom got ahold of him and chewed him out! Do everything through the legal system so he can't try to convince you he'll pay voluntarily.

I don't know if you've put much thought into feeding and diapering, but as someone earlier mentioned, breastfeeding is free I just had my third baby 2 months ago and this is the first one I'm using cloth diapers for - and it is so easy! Check out these diaper covers, I didn't want to even THINK about buying those all-in-one diapers that cost like $15 each, so I bought 3 dozen pre-fold diapers and a 6-pack of these:

http://nickisdiapers.com/catalog.php?category=65

and all you have to do is fold the pre-fold diaper in thirds and put it in the cover and put it on like a regular disposable diaper. Reuse the cover if it isn't wet/dirty and stick the dirties in a bag til you wash. And you can resell them when you're done I couldn't find used diapers on ebay for much less than I bought them from the above site brand new.

You still have plenty of time to gather all the baby items you'll need (and you really don't need much - your arms, boobs, diapers and clothes!). Someone mentioned getting diapers beforehand and I'll tell you this - different brands of disposables fit differently. My son wore Huggies and we bought some Huggies when my first daughter was born and they leaked around the legs! Pampers fit much better and I'm glad we didn't buy some big stockpile of Huggies before she was born.