and secondly can you do the back to school
and still get a printer with a $100 rebate
because if you get a printer under a $100 its free
Can't recall the answer to the first question, but to the second: yes, you can get the iPod and printer deals at the same time.
I got my first Mac that way (an Al PGB4 in 2003), getting rebates on both an iPod ($200 at the time) and a printer ($100). They were advertising it at the time as "up to $300 off if you get a Mac/iPod/printer together", they clearly want you to take both discounts.
They're fairly strict about all the bits having to be on the same receipt, so you can't, say, buy the Mac in-store and then order an iPod later.
With my second Mac, a unibody MBP in Nov 2008, I got $100 off a nice $150 Canon MP620 printer, but had missed the window for getting a free iPod (my PowerBook chose an inconvenient time to die).
They generally run the iPod deal during during the summer (ending in mid September), and the next revision of laptops will always get announced a
few weeks after the iPod deal ends (yeah, it helps them clear inventory). The printer deals seem to be offered much more frequently, and runs for longer periods of time.
It's worth poking around Apple's online store, clicking on the various ad-like banners, to make sure you know precisely what all the deals available to you are, before walking into an Apple Store (e.g. when I asked about the printers in-store, they showed me a variety of rebatable HP's; when I asked about the Canon I'd seen online, they had no problem selling me that instead).
I'm sure you already know this, but whether online or at a real Apple Store, be sure you point out you're a student to get all the "normal" academic discounts, in addition to the special rebate deals (alternatively, our university bookstore sells Macs already at the academic prices; I presume others do too).