Main tip (it's been a long long time since I went) if you can, sleep in a travel lodge or similar

Make sure you've got any file sharing off ,and the machines are password protected*.
Don't leave anything small and valuable at your desk, it didn't used to be an issue "back in the day" (I can't remember it being one at any rate), but they've grown a lot and I don't trust anyone
Other than that try and get sandwiches/hot food from the local takeaways and supermarkets as when we used to go to the Newbury ones the price on site was a rip off and the quality extremely substandard (things may have changed, this was around '02-05 but the burgers were appalling).
If you post in PC games you might get a better response.
Have fun
*When I went the biggest risk of an unlocked machine was one of my clam mates changing desktop pictures/screensavers.