I had a c-section with my daughter and new I'd have a nice long stay in the hospital so I made sure to be prepared. And I packed my bag based on a list I got from a baby talk mag. So hear are the things I found most usfull.
A comfy familure pillow it'll help your nerves and it's usefull when nursing.
A bra that open in front and a shirt that opens in front if you plan to nurse.
If you plan to bottle feed I sugest bringing in the formula of your choice.
A comfortable pair of slippers.
Your own pads because the hospital one tend to be uncomfortable.
An ipod or portable cd player and maybe a book or even a portable dvd played. You never know how long you'll be in labor and who just wants to sit around and stare at the clock.
You may also want to bring ice-pops the don't have and chuncks, hard candy, and/or gum. Because you won't be allowed to eat.
A breast pump, bottels and milk storage bags.
Your own toothbrush and toiletries.
And a cute outfit or two. One to bring the baby home and one for those cute little birth pictures that some hospitals take for you.
And a robe I didn't have one but I with I had. Lol.
I hope this list helps. Congrats!