I am not sure which thread to use. I want to partition my existing HDD (running Vista 64) so that I can create another place to run Windows 7 to see if I want to to switch or not. Not sure what pitfalls to look out for. Please let me know if I should post this in the Storage>Hard Disks threads.
More abouthard drive partition safely
Personally I use the linux tool gparted. I do all sorts of crazy stuff with it, like moving an OS partition from one drive to another.
I'm not sure what steps or advice you're after but google and download it, I'm sure it's up to that.