The Mac can read FAT32 without a problem. The Mac will read NTFS, but cannot write to it. There is a program called MacFuse, which can read and write to NTFS drives. The Mac’s file format of HFS PLUS is the best way o go.
HackZine.com goes into more detail about how to properly do this…
“If you want to share an external drive between a Mac and a Windows machine, you typically format the drive with a FAT32 partition. One problem you’ll run into, however, is that you can run into a file size limit if you’re dealing with really large files. NTFS gets around this limitation, but unfortunately the OS X NTFS driver only supports reading from NTFS partitions.
Thankfully, there’s a NTFS Fuse driver which you can use with the MacFUSE userspace filesystem driver. It supports full read/write capability, so you can use an external disk to swap large files between your Windows and Mac machines.
It’s a bit of a pain to install, but here’s the quick rundown:
Download and install MacFUSE – Link
Just get the DMG file and run the contained installer.
Download and install Fink. You need this for obtaining and building the NTFS Fuse driver – Link
– run the installer within the DMG file
– drag the FinkCommander application to your Applications folder
Get NTFS Fuse driver. You need to configure Fink to use unstable packages and then install the ntfs-3g Fuse driver. Open a terminal and run the following commands.
– /sw/bin/fink configure
Use defaults, except answer YES to use the unstable tree
– /sw/bin/fink selfupdate
– /sw/bin/fink index
– /sw/bin/fink scanpackages
– /sw/bin/fink install ntfs-3g
Mount your drive
– First, make sure it’s unmounted in disk utility (Applications/Utilities/Disk Utility – select drive – click unmount)
– Make a mount point: mkdir /Volumes/ntfsdrive
– Mount the drive: /sw/bin/ntfs-3g /dev/disk2s1 /Volumes/ntfsdrive
Replace /dev/disk2s1 with your external drive’s device. You can find this in Disk Utility.
The last step is all that you’ll need to repeat in the future to connect to your NTFS drive. After executing the mount command, the drive will appear on your desktop and you should be able to write files to it!”