Installing Linux on a Hard drive with XP
 

I have XP installed on one partition which takes up the whole hard drive. I want to install Linux and only Linux. How do I reformat the hard drive to install Linux. I don't want XP on there anymore.

What medium do you have to install Linux? If you have a bootable CD, the Linux installation will bring up a program that will allow you to delete the Windows partition and create and format new partitions.

And you might first think of saving any valuable data you might have on Windows, of course.

It's worth your while to get a good installation guide/walk-through for the Linux distribution before you install. Which version are you thinking of using?

the safest way to remove your XP partition(s) is with the same CDROM used for the XP installation.
I don't know about XP but the Windows 2000 CDROM when booted allows you to installs Windows2000 or to erase any Windows partition.
Use it to remove all Windows partitions, reboot ( so the changes will be saved ) and insert your Linux CDROM.

Most Linux distros are "newbiew tolerant" :) they will automatically create at least 2 linux partitions / and /swap

As a linux newbie, I would stay away from Debian ,Slackware, Gentoo and Linux from scratch
They are all great distros, but I would never recommend them to a newbie.
I would suggest Mandrake, Fedora ( I use it ) , Conectiva ( If you are from South America ), Suse.
But maybe the best option before scrapping your windows partition should be to download and burn a CDROM with Knoppix that you could run directly from the CDROM.

I think the safest bet is to use your Linux CD if installing by CD. Mandrake and Fedora as well as other gui oriented distros have the option of deleting the Windows partition and automatically creating at least two Linux partitions for you.