Brighton's a wicked place! had some of my best clubbing nights out down there.
Loads of great bars and clubs on the sea front, Honeyclub, The Zap and the Beach are my recommendations. There's a few decent pubs and bars, Allycats is pretty good along with a Western Front, Fortune of war & Fishbowl!
Brighton's full of alleyways and confusing roads so you may not come across many of the above! but head for the sea front anyway and you'l find plenty going on. Avoid clubs like the Event II & Creation.