Loading Redhat with a New Hard Drive

Hello all,

I just acquired a computer without a hard drive. I would like to 
purchase a hard drive and install Redhat on it. My question is, once the 
hard drive is put into the machine (presumably by simply plugging it in; 
I've never done this before), how does one install Redhat? It seems to 
me that at the point where the hard drive has been plugged in, the 
computer would not "know" it had a CD-ROM or a floppy drive. If that is 
the case, how does one get the software installed? Before I actually 
purchased the hard drive, I wanted to see if it would be 
straight-forward to install Redhat. Any advice on this would be greatly 
appreciated.

Thanks,
Ken