I can't help with the Windows 7 storage admin option, but if you do want to use gparted,
this appears to be a good tutorial. As I said, if you do it this way, I'd strongly suggest backing up your files first!
- Boot LiveCD
- Shrink Windows partition
- 'Apply' changes (I prefer to do these one step at a time, to be safe)
- Create new partition in unallocated space (I believe Fedora uses ext4 format)
- 'Apply' changes
- Install Fedora on new, empty partition (it'll likely be called hda2 or sda2)
- Enjoy!