Okay, let’s see what we can do. For starters, this is the correct forum for this discussion.
It’s going to take a bit of effort to get up to speed coming from a NetWare environment but it will be well worth it. You’ll have to rely a lot on the SLES documentation. Fortunately, I find it to be reasonably good. I suspect some of the problems you are encountering are with basic Linux concepts and the documentation is the best place to help with that.
Most of what you want to do is described in the SLES 11 Virtualization with Xen Administration Guide.
You can find step-by-step instructions here: 3.2 Installing an Operating System
You need to provide storage for your new DomU. That has to be a device known to your Dom0. It can be a disk (sdb, sdc, …) or a partition (sda5, sdb1, …). It could also be a file or you could do some advances storage management with LVM but we’ll avoid them for now.
Individual hard drives, RAID arrays, or Logical Volumes (LUNs) created when you setup your RAID array will each appear as a disk to your Dom0 (sda, sdb, sdc, etc.). If you have a RAID array and can create a Logical Volume, you can provide a disk whose size is appropriate for its intended use otherwise you will have to partition a larger disk.
To see what storage devices are known to your Dom0, run this command.
fdisk -l
That argument is a lower case “L”.
You can also use the YaST Partitioner to view your disks and to partition them, if necessary. If you intend to provide a partition to your DomU as the storage device rather than a raw disk, do not format or mount the partition.
You also have to provide the installation media to your DomU. Please, copy your integrated OES/SLES DVD to a directory on your Dom0 (like I suggested in the other thread) and use the ISO image when creating your DomU.
Remember, your Dom0 is likely installed on disk sda and is likely using sda1 for /boot, sda2 for swap, and sda3 for root (/). Make sure you don’t try to use those partitions for your DomU. 
If you have any additional storage related questions, switch to Advanced mode and paste the output from the above command between code tags (use the “#”) so we can see what devices you are working with.