The fresh out of the box MBP should not need any maintenance, and the iMac doesn't need any either, because you won't be moving the OS.
When you start up the MBP you'll be guided through a pretty straightforward process which will ask if you want to import your network settings and will give you the opportunity to import various other stuff, e.g. your apps and home folder, from another Mac via firewire, so the only thing you really need to do in preparation for the move is make sure you've got that cable.
