Hello KMG -
We use a white noise machine for ourselves, actually - DH & I can't sleep without some white noise in the room. I recommend a machine over a CD, as the CD's are short tracks that repeat, and you can start to hear patterns in the noise that can keep some folks awake. The machines are pricey but well worth the investment - we have the SleepMate, we use it every night.
I keep Bridget's room darkened for naps, but not completely dark. Her daddy was conditioned to sleep in a completely dark room when he was a baby, now he can't sleep at all if there's even a sliver of light in the room, so we're trying to avoid that for Bridget. I have blue curtains doubled with black sheers, which cuts a lot of the light and gives a nice comforting glow. We also make closing the curtains part of the "going to sleep" routine, which helps set the stage. Your baby might need it darker, or tolerate lighter - everyone's different, try out some different light levels and see which one s/he is most comfortable in.
Good luck!