I was going to write an entry that discussed What To Do and How To Prepare if you get sick, but then I found that it had been done for me, three years ago. Replace "avian flu" with "swine flu" or, really, any other human transmissible illness.
It's too long to cut and paste, and there are excellent suggestions in the comments anyway, so I'll just leave the link.
The only thing I would add to her list are face masks. These are incredibly cheap and easy to come by in grocery stores right now; however, should there be an outbreak of *anything* in your area, you'll likely be dependent on picking some up from the government. Just buy a few boxes now; they don't go bad.
Crossposted to my personal journal. Apologies to those who are getting it twice.