how to hang a Cado wall unit  

Hi cwise
I have not done those specifically but I have done enough wall units to see whats up. The rails will go right up against each end of that part that projects from the back of the cabinet. There will be pegs that run parallel to both the floor and the wall, which go under the projecting piece where you see the wear marks, partially surrounded by the metal. Be extra careful to mount the rails right-side-up with the end that has peg holes closest to it, at the top.

oh, and....
Those pegs probably aren't round, judging from the pic.
If you are lucky here you will find that the rails are designed to match the studs in your walls so that you can use wood screws. Be sure that they go past the drywall, which is likely to be under 1" and into the wood at least another 1/2" (more if you have wild kids). Electric stud finders are cheap and helpful. If you have to miss a stud, use butterfly nuts of at least a couple of inches. Just think it through before you insert any butterfly nuts into the wall.

Patience. ; )
I would wait for the rest of your unit to arrive.
I'm guessing it will come with the standards that attach to
the wall. It may make sense when you have all the parts together
or you may find that you are missing some hardware.
A google 'image' search will give you a hundred or so ideas of how
you may want it to look once hung. Most research i have done for my
unit suggested to lay it out on the floor and decide on placement.
That will also give you proper measurements for attaching to the wall
safely. Best to find the studs in the wall as the units are heavy!
Not familiar with your cabinet bracket. You may find a close-up in
some photos after a bit of research.
http://www.google.com/images?client=safari&rls=en&q=cado+wall+unit&oe=UT...

My system came with brass...
My system came with brass rods/pins @ 3.5"-4" long to hang the cabinets. The rods went into the holes in the wall brackets and the cabinets hang on part of the rod that sticks out. So, you insert one rod (into the hole) on each wall bracket, you then hang the cabinet so the lip of the mounting harware on the back of the cabinet is over the two rods. I hope this makes sense. I was short a few brass rods so went to the hardware store and had the same length rods cut from longer stainless steel rods that they had in stock. It is important that the rods are the correct diameter, or they will shift in the wall brackets causing the cabinet to sag or hang wrong. Lastly, it is much easier to hang these cabinets with two people.....it is tough for one person to line up the pins and brackets on the back of the cabinets alone.