We've had shiitake mushroom logs for a few years now. Once you get through the initial process of introducing the spores to your logs, they pretty much take care of themselves. We purchased plug spores and drilled lots of holes in 3-4 foot lengths of dead white oak logs. The spore plugs were inserted in the holes and then sealed with melted beeswax. It took a year to get our first crop.
We keep the logs up off of the ground in a shady place by our back door where we can keep an eye on them. My husband built them a swing of sorts under a bradford pear tree.
Once we notice the mushrooms sprouting, it takes about a week until they're ready to harvest. These photos were taken a day apart across a few days to show how fast they grow.
This is our spring crop, we're expecting another in the fall. They're a huge hit at our farmer's market and make a wonderful addition to risotto!