How can I stop NTFS-3g from mounting a particular volume?
Add the following line to the /etc/fstab file.

LABEL=BOOTCAMP none ntfs rw,noauto 0 0

If the label is something other then "BOOTCAMP" set it to what it is.

To edit the fstab file, in a Terminal: sudo nano /etc/fstab

To save the changes press control-O and to exit press control-X