Prerequisites for Kant?

I'm going to start reading the Critique of Pure Reason tonight, simply because it's been laying around in my room for almost 2 years now and I haven't touched it, which is irritating. Just wondering, is there anything that you should already be knowledgeable of before trying to read this? Any other philosophies or anything? I could look them up on the internet annd get the gist of them before I start reading this... thanks.