You need to understand how the drive is formatted, therefore you need to gather information about this drive. First, do you know what system type it was used for before? Such as Windows, MAC, or Linux? How are you connecting this drive? Are you attaching it directly as in using SATA or IDE? Or are you attaching it via USB? Please post your system log when you have this drive attached. A good way to get your system log is to use the following command in your Linux home login directory:
then post the contents that file, system.log in reply. If you go to advanced you will be able to attach a file when you compose replies.
Once you understand more information about this drive you can then use the mount command to mount the drive. If the drive is damaged, you may not be able to mount it, however let's assume that this is not yet the case and see if it is being seen by your system.