No matter what, invest heavily in lights if you are riding at night...
I'd recommend at least three tail lights (two superflashes, one on the bike, one on you, and a Planet Bike helmet mounted tail light), and three headlights, two very bright LED systems (NiteRider MiNewt X2's (one on helmet, one on bars), and a battery powered head light as a backup). For side visibility, retro-reflective film...
Riding my bike is MY pursuit of Happiness!!!