Best bet seems to plan ahead for the card you actually want to get, then have amazon, nvidia, bestbuy, and microcenter sites all open at once. Don't expect to be refreshing all day unless there's some hidden hourly quota that'll cause the sites to show "out of stock" for a certain period of time. I fully expect the Founder's edition to be sold out within minutes and the rest of the 3rd party models soon after.
edit: I'm considering attempting to get one on Thursday, and I haven't decided if I want to go Founder's or AIB. Make no mistake though, there will likely be no reviews out for the AIB cards at the time of purchase so you'll have less info on those models than what will be out for the FE cards.