I have never configured quota on suse, so there might be some differences from what I am used to.
First of all, you need to enable quota in your kernel. File systems -> Quota support, and choose v2. You will need some basic tools. They are probably installed by default, and if not I'm guessing they can be installed using yast.
I don't know where you want your quotas, (spool, home folders or whatever. But that isn't very important). Then you add usrquota to /etc/fstab on the options field on the partition you want to use quotas. For the changes to take affect, you need to remount the partition or reboot. If the destination is /home and it is a separate partition you might have to enter runlevel 1 to be able to remount it.
mount -o remount /home
The quota data is stored in the aquota.user file in the root of the partition you want to use quotas. This will not exist automaticly, so you have to create this. i.e:
This might take a while, as it is calculating used space and inodes of each user. When it is done, you can modify this file by hand, or use the tool edquota. (edquota <username>). You can have quotas for groups aswell. This is stored in aquota.group.
When this is done, activate quotas with quotaon.
This is a pretty basic description. And it might not work just like this as I have never done this on suse. But anyway you have some clues on how it is done