Well this rack is going to be in a room, and I desire to look similar to other pieces of furniture. Here is a crappy web pic of the coffee table.
My thought is to get some wood and cut out a number of shelves, then to use craft legs like these to separate the shelves.
Then stain to match the color.
For the back, it is hard to explain, but picture 2 L shaped pieces of wood that bracket each rear corner. I envision each being about 4" by 4". Then for the actual back, another piece of wood that spans the back sections of the L.