Various things have been said about how you may have to order a "console bundle" or you that you can't use trade-in's for your pre-order, etc. It looks like some official information has finally been released.
Starting Oct 10th at 10am, EB Games and Gamestop will start taking pre-orders for the Sony PlayStation 3 console. There are a limited number being accepted at each store because of the extremly limited supply. They don't want to have another Xbox 360 pre-order blunder like they had a year ago.
So, if you've got USD $100 burning a hole in your pocket, get to your local EB Games or Gamestop early tomorrow morning. If there's 15 people in front of you, it's probably not worth standing around waiting because you won't get a system (and they may cut off pre-orders anyway.) So either get there early or wait for another opportunity.
They will accept cash, credit cards or trades for your $100 reservation fee. Getting on the list, however, does not guarantee you will get a launch system! It means you potentially could, depending on how near the top of their list you are and how many systems they get. It's also of course limited to one per household.
EB Games / Gamestop will start taking online pre-orders once game and accessory availability has been confirmed. Online orders will be filled independantly from in-store orders. So, if you miss out on the in-store pre-orders, keep watching the website for your opportunity to do it online.
Source's here