Industrial looking hanging media shelves

Step 2 Design and sketchs

Tools:
Pencil
Ruler
Compass
High School Math... that I need to look up on the internet now.

Materials:
Paper
Eraser

First thing I always do is sit down and draw things out till I get something that makes sense, then I refine it and create more detailed drawings where needed.

Here are my refined drawings.  The first image is the board details.  Where I wanted to put the holes and cuts with measurements.  The there a 3/8" wide by 3/8" deep hole cut into the boards at six locations, four on each end and two in the middle.  Then I would cut a 1/8" line into the board so the wire will be able to slide in, and the stopper fastener can sit in the 3/8" hole.

I would probably change a few things from this drawing.  The holes/cuts on the end of the board were too close to the end, I had a couple break on me (although gluing them back on was fine).  Probably 3/4" to 1" from end of board would be better.

Second image is me calculating where to put the stopper fasteners on the steel cable.  A squared + B squared = C squared. 

VERY IMPORTANT: Make sure that the hooks are attached to a stud or top plate!  Doubtful it will stay up otherwise.

The last image is the jig I made so I could easily and consistently drill the 3/8" holes on the 1x6 board.  The wood with the 3/8" holes in it needs to be some kind of hard wood.  I just picked up a scrap piece of oak up from home depot.  It needs to be hard wood so it will hold its form longer.  If this was pine it would just get torn up very quickly.