I tried my hand at mushrooms this fall-Oysters. I got the inoculated plugs from a local mushroom grower. I came across a tree crew cutting down an oak and asked them for a few logs. Those nice guys loaded it for me! We'll see next spring/summer or the next if it worked.
Ziffa was correct in giving advice. Use fresh cut wood, the harder the better. Don't use cedar or pine. Drill the holes just big enough to accommodate the plugs and then seal with bees wax or paraffin. The smaller in diameter the log is the sooner you will get mushrooms. So if you would like a succession of mushrooms over numerous years, use varying diameters of logs, but not under 4 inches. Hang, stand on end, prop them up on a fence, but don't lay down the logs. You want lots of air flow.