lets be honest. will smith did a good job in the movie, but his character lacked common sense. hopefully, this instructable should help you if you ever find yourself in his position.
Step 1: materials
military vehicles: there should be plenty of humvees and tanks left in the city from the
former military presence. don't take the Robert Neville approach, and
take a crappy station wagon.
sports cars: leave the ford mustang. its not worth the repairs you will need to make,
especially when it breaks down miles from the shop. take a ferrari
guns: a sniper rifle does have its advanteges, but a rocket launcher works much better
for large groups. also, dont only take one grenade.
food: forget the food in stores, it will probably go bad in a couple of months. there are
probably plenty of military foods with a shelf life of about 30 years.
computer: dont use a macintosh.