I have black-out curtains (doubled up) and no light sources in my room (even my alarm clock is covered up) but still have issues sleeping since it's light out when I leave work. Magnesium supplimentation has helped me greatly, though, so I definitely recommend that. Also, be sure to get as much sunlight as you can after you wake up to get you going for the day.
I have had very little caffeine in the last 5 months, which makes working the night shift even more difficult. On that note, though, be sure to avoid decaf green or black tea, as it has a relaxing effect and may make you more tired.
I wish I liked to eat liver.