There's information in the Help system in WinXP, but it's hard to find.
Open the Computer Management tool in Administrative Tools. Bring up the Help function in Computer Management. In the Contents list is Disk Management. Expand that, and the first sub-item is a Checklist for adding new disks. Click that, and the "Add the new disk" item will give you two options, using the Command Line or the Windows interface. The Windows interface is of course the easiest way.
When it says to use Device Manager to scan for hardware changes, you can first check the Disk Drives section to see whether your new disk has already been detected. I've usually had to manually scan for new hardware as the instructions say, when installing a new hard drive; I'm not sure why it doesn't automatically load new drives. If your new drive is already listed, then you don't need to scan for hardware changes and can go to the next step.
Once you Rescan Disks, the drive will show up in Disk Management, and you can then do any partitioning and formatting you need to do. If the disk shows as "Uninitialized", you'll need to initialize it, just right click the disk label and select initialize.