Buy beer and protection.
Take breakables, valuables and favourite things out of one room and put them in another, IE your parents room, then you sleep in that room at the night time.
Only invite people you like and trust.
Have plenty of food ready.
And cleaning stuff. (we had to clean the road after one house party at a mates... god knows what we did, I think it was a food fight.)
Be sensible.
Drink slowly through the night.
That's about it really.