For this project I made a set of three shelfs with a charging station in the middle. I used particle board and dowels for the structure, and hot glue to keep things in place. Here's a picture of the final result.

Step 1: Required Materials/Tools

Approximately 700 square inches of wood. The wood I used was ~0.5 thick and already finished, but you can use another type. Make sure the wood can be cut into 4 13x13 squares.
~240 inches of a sturdy dowel. The thickness can vary, so just make sure it will be able to support the structure.
Hot glue gun and glue.
A drill to make holes for cable management.
A saw to cut the wood and dowels.

Step 2: Cutting the Wood and Dowels

Cut the wood into four 13x13 squares. These will be the surfaces of the shelfs. Try to conserve scrap wood because it can be used for additional support or for the charging station. Next, cut the dowels into 15 inch segments, and at a 30 degree slant. The slant is so that the dowels will glue in place better when the time comes.

Step 3: Making the Charging Station

The charging station can be customized for your specific needs. Personally, I made 2 slots for laptops, and 3 slots for a phone and other smaller devices. Additionally, I drilled a series of holes in a piece towards the back that I used to route all of my cables. I won't go into too many specifics for this step because It's really based on your own personal needs. Just make sure you check for clearance and make sure everything will fit.

Step 4: Gluing Things Together

First, glue all of the pieces for your charging station into place. This should be done before you begin gluing the actual structure together. Next, glue the ends of all of the dowels to each of the corners of the wood to form an X. I also glued the intersection of the dowels, but that step probably doesn't help much. If you have any additional wood left over, you can glue it to the back for additional support.

Step 5: Finished Product

Here's a picture of the shelfs in use. I highly encourage you to customize your own shelfs to meet your own needs. Although this is a template for some basic desk shelfs, there is plenty more you can add to make them your own.