It might be wise to begin accumulating basic necessities to last for up to two weeks around 21 21 2012. There may be a general panic created by fear and confusion around this date. This may start to occur 3-4 days before 12 21 2012. Grocery stores and survivalist outlets may become denuded of goods at this time. Because this date is also 3 days prior to Christmas, such a general run might go unoticed.
Beginning around the first week of November, you might choose to begin to slowly acquire all the basic goods you might need to last you up to at least two weeks. Do this very slowly over the next 6 weeks, so as to not promulgate the very panic in the first place. If nothing happens at all, at least you will be prepared. You can always access these goods anyway. Better to be wise and safe than sorry.