Keep it off the ground. I used thick paver stones here, but cinder blocks are better. Another mistake I made, I should've used treated 2X4's, carpenter ants and other bugs don't like treated wood.
I've made another one next to this one, and I sprayed the ground , the blocks, the 2X4's with Taurus S/C , which is actually 9% fipronil. Same thing as Termidor. That killed out a carpenter ant colony and pretty much eliminated the bug problem. I sprayed all of it BEFORE putting wood on the rack.
I've also located this in a far corner of my yard, as far from the house as possible. Due to the bug issues that wood will attract. I also put it in a place where grass won't grow due to it being shaded, that helps with the bug problem.
The wood in this picture is what's left of a pecan tree my Father-in-law cut down. Depending on what size splits or chunks you want to use, there will be tools to help. I use a cheap Harbor Freight electric chain saw, a
Kindling Cracker , and a miter saw.
I have a stick burner, so I go through a lot of wood. There's some work and trouble to it, but its worth it. I've since added a good amount of oak when I saw an oak tree being cut down up the street.