Though not the sturdiest choice, wooden doors in "Minecraft" complement brick houses, creating a result that mimics a real-world house. They're also the first kinds of doors you can craft; the alternative uses iron ingots, which would require special tools in addition to the ones you begin with.
Crafting a Wooden Door
With six planks of any type of wood in your inventory, interact with a crafting table; fill the first two columns of the 3-by-3 crafting grid with the wooden planks, creating a single wooden door you can place on the ground. Although you can place a door on top of any physical block, it doesn't serve much purpose unless you place it between two walls. Interacting with the door, just like the crafting table, lets you open and close the door at will.
Improving Door Security
When you explore the world of "Minecraft" and eventually gather enough iron ingots, you can make an iron door using the same process. Until then, you'll need to get creative with security; try building a deep lava pit with a cobblestone bridge you take apart every time you go through the door. This way, any unwanted invaders will be greeted with an equally unwelcome surprise.