How to open a door in minecraft is this:
1. Open minecraft.
2. Open a server or single player world.
3. Find or make a door.
4. Click on it. Doesn't matter if it is left or right
5. Walk through the door.
If the door is an Iron Door, follow the above up to step 3. Iron Doors cannot be opened by clicking on them, they can only be opened using a charge
press Lt or left click it
just tap the door
Iron doors in Minecraft have to be open with redstone mechanics. So to open the door you would have to connect a lever, a pressure plate, or button to the door.
You have to right click.
something called silverfish will be able to eat wood. now zombies can break down doors! And villagers can open doors. Now in 1.2, zombies can break through wooden doors, not iron doors. And if you are playing in a PvP minecraft server, an enemy faction(army) can overtake you territory and open your doors. Also if there are wooden pressure plates outside the door mob can stand on them and the door will open.
To open an iron door you can use a pressure plate lever button (reccamended) red stone torch/powder detecto rail
You can create a door by doing the following: ("Plank of wood" is "pow") in the 3x3 crafting square: pow;pow;nothing pow;pow;nothing pow;pow;nothing then you right-click on the ground where you want the door to be. Right-click the door to open/close it you should use minecraft wiki, it would answer all your questions
To open or close a iron door you need a redstone signal to activate it. Some different blocks you can use to produse a redstone signal is a button (wooden or stone) pressure plates, light sensor, or lever.
Iron doors are normally in the closed position. To open it, you have to run 'electricity' or redstone to the block that the door is resting on.
you cannot directly open a door with a command,but there are ways to open doors with command blocks:like have a command block next to a comparater (in the snapshot at mojang.com) and have the command block reapatadly get powerd by a clock and in the command block have:/testfor @a/p/f/r[selectors] and wire the comparator to the door and when someone meets the testfor selector the door opens!
To make a door on the ground.
Windows XP: Open the start menu, click "Run" then type %appdata%. It will open a folder with Roaming in it. Open that, and then click on the .minecraft file. Windows 7: Open the start menu, and then type %appdata% in the search bar. It will open a folder with Roaming in it. Open that, and then click on the .minecraft file.
If you don't have Minecraft bought, then buy it, then open minecraft, and it will update to 1.0.