Hi RichC.
I probably do more night diving than day diving at the moment, purely because there is so much more to see and because there are more fish around. The best tides I found for diving are the last three hours of a rising tide, thats when the fish seem most active.
Any torch will do, but in the UK, the brighter the better. Take two if you can, a main torch and a small back-up. Kit wise, try and adopt the KISS principle. Keep it simple. If you don't need it, don't take it. And is you do take it, make sure it's secure and can't fall out or off.
Dive with a buddy, unless you can really help it. Night diving is inherently more dangerous than day diving. Just having someone shine their torch on you whilst sorting out a fish is a real help. If something goes badly wrong, then they could save your life (or ring the emergency services to start a promp search).
Let someone know where you are going, and roughly how long you will be in the water. Go somewhere local that you dive in the day for the first few dives so than you know the ground
Most importantly, enjoy yourself. On a calm summers evening, no crowds, warm water, a starry sky and phosphoresence, there is no better place. Don't go too deep, and look for fish where you might not find them during the day. I get most of my bass at night from a featureless rock shelf. You won't see them there in daytime. Flatfish will be over the sand as usual, but will be closer in, with many more species to see.