A comic about the secrets of Astroban leads you to the spell book with the Command Block Calculator. With this you can build in Minecraft like the pros.
Each CommandBlock contains a command that can become very complex. For this you need:
English names of over 300 blocks
an option number for color, stone type, wood type, or orientation for many blocks
an option for setting the blocks (solid, hollow, replace,...)
absolute or relative coordinates
Commands (summon, setblock, fill, clone, teleport)
With the CBC you can do it all very easily.
All steps are well explained.
You copy the command from the CBC into the CommandBlock in Minecraft.