As you've been told, pretty much any USB keyboard and mouse should work OK. However, I would strongly recommend obtaining an Apple keyboard rather than go with a run of the mill USB keyboard which for the most part are designed primarily for Windows use. You're going to need specific keys such as the CD\DVD eject, Command, Option, and the various keys for F and FN functions.
While there are equivalent keys that you can use on any USB keyboard, it can and will become confusing. As for the mouse, any USB two or three button mouse works fine. I'm using a Logitech optical with my MacBook and an Apple wired aluminum keyboard.
Regards.