I'm trying to find topics on how to build a huge castle but there are no specifics on how to build one. What I would like to know is how much material was used in constructing the castle. If there is anyone who knows that would be awesome
There are no specifics because it comes from the builder's imagination. I seriously doubt anyone would have a step-by-step, block-by-block instruction guide to their creation. And it would be boring to completely copy someone else's work. Look through the Player Creations & Screenshot section for ideas. Or, look in the Maps section for worlds with pre-built 'castles' and save yourself some work. There's also a couple of 'show us your base' threads, one in General Talk, one in News & Features.
Like Tunnel King said, look in the Play Creations and Screenshots for ideas that spark in your mind and then go create them. They can be made up of anything as its your castle.