There’s two types of play in Minecraft. There’s Creative, where they just give you a world space and all the blocks and let you go nuts. This is basically digital legos.
Creative mode turns off the dangerous monsters, especially the exploding shrubs known as Creepers. Those assholes do a real number on the stuff you’re trying to build.
Then there’s adventure mode, which plays like a sandbox RPG. Monsters will kill you. You have to harvest all the stuff. Creepers will blow your shit to rubble.
There’s not a whole lot to figure out here, once you show him how to acquire materials and make/use the crafting benches. He can look up all the item recipes, or he can experiment, whatever floats his boat.
Five year olds eat this game alive. I would bet that your kid goes nuts on it, and also, that maybe he will want to start reading about it. It has that effect on kids. They love being able to build stuff, like in a normal legos playtime, but here, the stuff is in 3d and they can get in there and move around in first person mode. Also, sometimes, the stuff fights back, if they’re into that sort of thing.
So I’m sure your kids will dig it.
If he likes it, he and his friends can get together and play on their own server (there’s a nominal fee for that, per month). The you can set up private servers, but the easiest thing is to subscribe to Minecraft Realms. This gives you a private server run by Mojang (the company behind Minecraft). You will have admin rights to this server. You can invite or kick people as needed and you set the rules for the server. This costs $8 a month and you can have up to 200 people in your server, so that covers your kids and one they invite. This is much safer for your kids than playing on the public servers.
Right now Minecraft Realms only works for the PC/Mac version of the game. Eventually it will come for the mobile games, which are known as the Pocket Edition. For that reason, if you tink your kids might want to play with friends, you’ll want to get the full desktop version.
Here’s more about Realms -