My son is building a beer pong/corn hole set. Basically this:

http://www.curvesatbethany.com/wp-co.../2015/08/1.png

The circular holes need a ledge to hold the inserts.

I'll begin by saying that he already bought 1/2" plywood and cut it to size *before* he
called me about cutting the ledged holes.

So here's what I'm going to suggest:

1 - Glue a piece of 1/4" tempered hardboard to the topside of the plywood.
2 - Use a circle cutting jig and an up-cut spiral bit to cut the circular holes through the now
3/4" panel. (He's planning on making a circle cutting jig for his router)
3 - Use a slot cutting bit, with the bearing riding on the plywood to create the ledge by cutting
away the hardboard top.

A quick look shows that Amana makes a slot cutter that will cut a 1/4 inch "slot" (in this case,
the ledge) to a depth of 3/8€�. I'm sure there are other slot cuttings bits that will work.

4 - Cut the insert disks from 1/4€� hardboard.

Does that sound like a workable plan? Have I chosen the right router bits for the task?