1. First you need to create the partition. Go to YaST and then click on System -> Partitioner.
2. Next, click on the partition you want to resize and click on "Resize". Once you select the new size, you will have an amount of unpartitioned space.
3. Create a new partition.
4. Create a new partition (had to do it twice ... once the space has been assigned to a partition), of course select your desired fs format etc.
5. Once you have the partition, move your home directory, say if you have /home/user, move user.
6. Go to /etc/fstab and edit it
/dev/newpart /home ext3(or other format) options 0 0
Note that you must change the second 0 if you want fsck to check it. Under options you've got to include the same options you would with mount. I have "defaults" there