If you read up on it and talk to other divers, you'll probably get most, if not all the information you need. I've had several enjoyable night dives, and haven't had any special training in it. I have a good primary and backup light, keep a glow stick on my tank valve, and leave a marker light on shore.
After reviewing a few light signals (move the light in a circle for "ok?/ok." or in a vigorous back and forth motion for "there's a problem/I need your attention", etc.), I found night diving to be easier in many respects, as it's easier not to lose your buddy at night, it's easier to communicate with them at a small distance via light signals, and there are (at least here) a lot of creatures that aren't as active during the day.
Task loading is always something to look out for, but I actually found my first night dive to be quite relaxing... I had one of my best air consumption rates ever.
Just make sure you're prepared.