Mostly what others have said, which is: metrics are now going to become very important. The nice part is that the actual department is much easier to maintain than Office Supplies, but in its place are sales. Things like SquareTrade—which you're probably already fairly familiar with—and More Accounts are going to be tracked a bit more granularly, and you'll be expected to hit a certain percentage and/or number of plans/accounts per shift (which isn't as bad as it sounds). Plus things that you may not be as familiar with, such as Tech money (e.g. when people pay for diagnostics; must hit budget each week), Market Basket ($195 is the goal to be added on to each laptop to make selling them profitable), Liquid Armor (beaten to death, but will now be a sales goal for you), Ink Attach (percentage of printers that are sold with ink), and PC Premier Setup/Virus Shield Attach rate (services that you should ideally be attaching to a good percentage of computers that go out the door.

It may sound like a lot, and it is to a certain extent. But you'll get better at it as you go. Just focus on improving one thing at a time, and always ask questions if you don't know. I find if you don't have to focus on what you're selling, you can focus much more on how you're selling, and it makes it much easier not to have to juggle the two. Absorb as much info as possible, and the rest will follow. :)