I'm a total newbie but, starting from an XP system with 1 large NTFS partition, what I did was:
- Defragged XP
- downloaded the iso of System Rescue CD from http://www.sysresccd.org/download.en.php
- Burned this to a cd
- This gave a bootable CD, with QTParted on it.
- Booted to the CD, used QTParted to shrink the XP partition
- Then used my distro (Slackware 9.1) setup to setup the new partitions in the space - in the case of Slackware, they use fdisk, or cfdisk
This worked, and it's all free (as in beer, not just speech)