Everybody knows the obvious things to stock up on: water (fill your bathtubs), canned goods, pet food, gas, flashlights, medications. One thing that may not be obvious, and that we desperately needed after Katrina and the federal levee failure, was CASH. Most ATMs weren't working, and most of the stores that were open at all couldn't take credit or debit cards for several days. Also, if you have a land line, get a non-cordless phone to plug into it. These worked for many of us when power was still out and cellular networks were down.
Be as safe as you can.