Minecraft is a very fun game with a vast amount of possibilities. You can expand those possibilities with mods, such as the Web Displays mod which allows you to use the entire Internet in your game. In fact, Web Displays is exactly how I'm posting this.
The Official Minecraft site! When you download Minecraft it is perfectly safe. No malware has ever been found with Minecraft. Ever.*
*Beware of things that do not come from Mojang AB. Those can have fake minecraft launchers or mods and can actually be malware.
I'm fine with singleplayer, but when it goes to multiplayer
The community is full of bullies/trolls, griefers, and hackers.
They can even make a 23-year old man go smash their computer.
So beware of "people".
(Rating based on software)
Be careful with your kids.