[dnanian]

There are a ton of examples of how to partition on the forums, procket, so do a bit of searching and I think you'll find exactly how to do it. The key is to make sure you partition as "GUID". It's easy to do.

Renaming the disk is also easy - you use Finder, and name it "Macintosh HD", yes, if that's what it's called now.

Once you start up the computer again, make sure you select the new internal drive as the startup drive in the Startup Disk preference pane.

You're going to be surprised at how easy this is. Don't worry, but treat your old disk with care until you're sure you're happy.