Here is a file that I pulled up from the forums...It was VERY helpful for me!
Start up your computer and enter into the BIOS (Usually by pressing delete a few times when you start your comp)
Somewhere in your BIOS (Generally under Advanced BIOS features) there will be an option for you to change your boot sequence. RIght now it may look like this; Floppy, HD-0, CD-ROM. You want to put CD-ROM at the top of the list.
Put in your windows XP cd and SAVE and exit the bios. When it starts back up watch the screen for any messages about booting from the cd. A blue screen should come up that guides you through the rest. (Make sure you delete ALL your partitions if you want to remove everything and format using NTFS)
Although windows XP guides you through everything, you need to know whether u actually want partitions or not. With a harddrive your size, i would partition about 100 gigs and leave 60 for my windows/program files/documents and all that crap. Then leave 100 for all your media. This way, when you want to format again you can just leave all your stuff on your 100gig partition, and just reinstall on the 60. Again, the windows xp setup will guide you through the partitioning.