I have a external 500Gb usb disk with 150Gb EXT3 and remaining NTFS which I
keep for installs etc

My old NOWS SBE 2.5 box handles this by default - no hoops to jump through

what do I need to do to mount a NTFS disk on SLES11 SP1 with OES installed ?

mkdir /mnt/usb
mount -t ntfs /dev/sdc2 /mnt/usb