I worked a rotating shift for 7 years, and am now just really starting to wonder how much havoc it played in reducing my overall gains from lifting. It seemed I'd have a solid workout routine, get a decent amount of sleep, and eat a good diet, while supplementing with useful products, but still not see the kinds of gains I would have liked. I've recently switched to straight days, and have found that a steady sleep schedule is indeed much more important than I would have previously given credence to.
I don't think working nights should negatively affect your progress all that much, if you're consistent in your sleeping hours. The tips offered from others here are all good ones, especially the blacking out of windows in the room you sleep in. I found black garbage bags, while looking like complete ****, do a great job of darkening the room. A steady source of white noise is also a godsend when sleeping during the day, in order to block out the noises that are more likely to crop up during the day as opposed to the evenig. A fan works nicely, I personally find my computer is a good source of steady background noise.
A little while back there was a discussion about cortisol levels being higher in people who sleep during the day as opposed to sleeping during the evening. I'm not sure if I buy into that or not, but it may have some truth to it. Oddly enough, I found that the quality of sleep for myself tended to be better when I slept during the day as oppposed to during the evening.