re-partition my hard disk

["rocky" <rocky2winnie@gmail.com>]

Hey all,

On my PC I have 2 hard disks. The primary one has Windows XP
installed. Afterwards, I decide to learn Linux. So I got another Hard
disk and installed Debian stable successfully on it. Now, I'm thinking
of make my PC serve as the file back up server for my home office.  I
will install backuppc in my debian stable. Till now my secondary hard
disk is not partitioned at all. I'm thinking of partition the hard
disk so I can allocate a separate portion solely for backuppc. Can any
of you give me some hints on how to accomplish this please? Does the
partition have the risk of wipping my debian stable system out? How
can I prevent this please?

Thanks a lot in advance!

Rocky