Pretty much like Tex says. I planed the lumber. Jointed and glued it into 3 panels plus two shorter side panels, then sanded panels. Start at top panel, mark the center. Use arch template - you may need to make a template for an arc using a string and pencil of course. Determine how wide you want the top to be and trace the arc across that board. Measure your way across the arc marking an x as you go for where the holes will be. I used 3/4 forestner bit for the through holes as I find it fits every size pen easily. Drilled all those holes, then cut the line of the arc and you have half a hole. The next layer measure up from the back maybe 1.25 " and set back of the top flush with that. Mark all the holes, these are for your bottom holes, 1/2" forstner bit drilled maybe 1/4" deep. Come ahead another 1.5" or more if you want and trace the arc again, drilling the 3/4 holes....cut, then to the next layer and so on. The sides simply have dado's that hold the shelves in. I think 3" of space between shelves is pretty good to hold any pen that isn't a midget. You can put a drawer in the bottom to face the back of the display like I did, or not bother, which would mean your display can sit lower. My drawer is 4.5" deep. I can't take a photo of the drawer without moving the stand. It's nothing special to see anyhow.
Now...you can recycle the other halves of the panels with the holes drilled all the way through. You can make a matching stand with an outward arc instead of an inward arc! That's what I'm doing. My other stand will not be so deep and not have a drawer, which I don't need 2 drawers anyhow.
