I was surprised at the amount of different formations, their textures, colours and shapes. Steep, but navigable steps rise up to the cave entrance. There is a rest-spot on the way up and most people will need to stop there for a breather.
If you can, take your own torch as they only had two for hire when we were there. They were not really adequate, especially when one of them wasn't working so well. Lighting is being set up in the cave, but I think it will be a while before you don't need torches.
They have a guide, but he only speaks Thai, so unless they get someone who speaks English, you may need to have someone who speaks Thai to translate or do a lot of research before you get there. I would still recommend a guide, just to show you the way in AND out of the cave. It really is very big. The guide costs about 150 baht.