Apple has posted a Black Friday page on their website alerting people to special sales coming up. But they give no detail. They'll be hard pressed to match the great deals being offered by big-box retailers such as Target and Walmart.
My recollection is that in the past they'd cut the price on an iPad $50. They don't typically offer a special price on the iPhone. The page suggests that you browse beforehand, and then show up on Friday to take advantage of the deals. And it says you can shop online, and then pick up your purchase at an Apple Store. The fine print says the sale will go from 12:01 a.m. PST to 11:59 p.m. PST. The promotional pricing can't be combined with any other offers. For the best Black Friday deals, see my previous posts here and here.
The website TUAW is also now tracking Black Friday deals.