wood - 1" x 8" x 36"
paddle drill bit - 7/8" and 1 inch
dowel rod - 7/8" x 6 inches
stain or paint
Cut blocks into the following sizes: 6", 5.5", 5", 4.5", 4", 3.5 and 3".
Once squares are cut use a ruler and pencil to draw a line from upper left corner to bottom right corner. Rotate square 90 degrees and repeat. You will now have a "X" on your block which is the exact center spot for you to drill your 1" holes.
Using 1-inch paddle drill bit, drill holes in all BUT the 6" block.
The 6-inch block will be drilled with the 7/8" drill bit. Do NOT drill all the way thru wood block.
Sand all pieces, center holes and round all edges. The wood is satin smooth once I finished with all the sanding.
I left the dowel natural and rubbed on bee's wax. I painted the blocks with a water based stain.
Once everything was dry I used wood glue to insert the dowel into the 6-inch block and let dry 24 hours.
There is a great tutorial with many photos available here. They even have a flower shape stacker.