Yup: I have a pile of rolls of Ilford XP5, which is ISO 400, ready to load into the Nikon EM, together with the 50mm 1.8 for photography when baby arrives - if I rate it at 800 or 1600 (B&W film speed is more-or-less a suggestion, you can alter the effective speed by changing the develoment time)  I should be able to get smooth enough pictures in available light in the hospital. I don't want to be using much flash on a newborn. I'd like to create some artifacts recording the event, not just collections of photons on a member card.

I was also trying to avoid too much jargon at once. You'll notice I didn't mention large vs. small apertures as opposed to large vs. small f-numbers.