What should I look for in a snowboard?

I'm pretty new to snowboarding, I rented a board (probably a piece, no idea make or model) from a shop but I think I want to get my own board. What do I look for? What brands are good, what do different features (long/short, wide/narrow, etc.) mean. And if I wanted to get a quality board on the cheap, how much should I look to spend. Oh and bindings and boots too, what do I look for there?