Preparing a drive for use is a two part job. Firstly you partition it and then format it. You can right click on ‘My Computer’, and click ‘Manage’, click on ‘Storage’, and then you can manage the partitions in that menu.
As a warning, you cannot delete the main partition windows is installed on while in Windows. Not sure why’d you want to anyway, but you can’t. If you want to repartition the drive and reinstall Windows, you’ll need to restart the computer with your Windows CD in the drive, and boot off of it.
As for the other hard drives that may show up, once you delete and repartition, any data on the drive is gone, so be careful.