I got a few followup questions from my friend after my response to his request for advice about baby photography, so I figured I might as well put my additional answers up here too:

Should I be taking the shot in B/W or converting it later?

I always shoot in color and convert in software later. That way you have both options. If you shoot in B&W in the camera then you are stuck with it. But if you shoot in RAW (rather than JPG) then it doesn’t matter. The preview on the back of the camera would be in B&W if you shoot in B&W mode (which can be helpful to visualize the image in B&W), but the actually file will have full color and you can do whatever you want with the file.

Lens Hood required with the 50mm?

I use hoods on all my lenses to help protect the lenses if I drop them. The hoods for the 50′s are so small that they don’t really help much for flare or reflections. You can get after-market hoods for most lenses from stores like DealExtreme.com for less than $10 (compared to 2 to 3 times as much for branded hoods from Canon and Nikon), so for me it’s a no-brainer.

I have the 580EX [flash], should I be leaving it at home? Or is bouncing flash of the ceiling OK to do in low light?

Nice flash! I carry my flashes with me all the time and I use them a lot. I pretty much only use them by bouncing off the walls or the ceiling (or off-camera in a Softbox). It’s a different look than ambient only, but if you’re careful with it then it can still look very good. I probably use a flash less with my 50 than with other lenses, but I still use it a lot. You may want to use it at the hospital, but they may not be very happy with you if you do. I would definitely take it so you have it if you need it! After you bring baby home then you will be shooting so much that you should experiment with flash and no-flash and see what you like.