One of the first things you want to do is to make sure that you have everything backed up (and not just on a disk but on paper as well). Make sure you have a back up of at least the following.
1. Your clients - all their information.
2. Your vendors
3. Your calendar
Make sure for these backups you have one in a safe place, away from your office, put one copy of these in a get-away bag. Something you could pick up quick on your way out of the office.
Enjoy your day.