What's a bonus chest?
You can give your kids a headstart by creating a new world which already has a chest waiting for them, with some randomly selected items inside to help them get started.
How do I make one?
1. Launch Minecraft and create a new world (by selecting Create New World and More World Options)
2. Click on Bonus Chest to toggle between the ON and OFF settings
3. When you launch your new world you'll find a chest surrounded by torches waiting for you close to the spawn point. Look around, it won't be far away but keep in mind that it could be underwater or blocked by trees.