pick up the drive. Look at the end that you plug your IDE cable into (the cable that goes from your drive to your mobo). Look just to the left of that. You should see 2 rows of pins 4 long. (5 on one row, top I think). You should then see one or more "jumpers" that plug into 2 of those pins. On the top of your drive you should have a little chart that tells you what pins to cover with the "Jumpers" to make the drive Master, Slave or Cable Select. If this is a second drive, then you want to go with Slave. So cover the pins that the chart tells you to, mount it in your case, plug in the IDE cable (assuming it's not SCSI) and plug in the power.
When you boot make sure it shows in your bios, (might have to make sure by going into the bios and switching that IDE slot to "Auto").
Get into windows and format it. All done.