Here's my plan so far:
Defence:
Steel grills on windows and doors
Stairs rigged with C4 (in case of property breach)
Shotgun and 12 boxes of ammunition
9mm Pistol and 500 rounds of ammunition
Military spec Machete (Black Blade)
Seige:
Attic stocked with 1 years supply of water and dried / canned food,
SW radio, Cycle powered generator in bedroom 2, Assault Rifle with silencer and 1000 rounds of ammunition, weights, books, MP3 player
Escape:
250cc Dirt Bike parked in garage with spare fuel cans on panier racks
Military spec Machete (Black Blade)
9mm Pistol with silencer and 70 rounds of ammo
.22 Rimfire Rifle with silencer and 200 rounds of ammo
Crossbow and 12 bolts
Full pack with everything tied down to avoid rattling
Water
Food
Maps
Defendable position:
Aiming for Warwick Castle
Oh and yes I've read the book!