Don't be a hermit, keep your door open while you're unpacking and chat to people, being a "facebook whore" and chatting to loads of people on facebook before you even get there is a very good thing to do (in my experience), BRING FOOD (it makes you popular), and you will most likely get freshers flu so prepare now. Also, refrain from any references to TV programmes/films because your flatmates will not know the "Always take a banana to a party" rule, and this will result in them sellotaping bananas to your wardrobe. That's all I can advise you on now, you'll be fine!