To create a document go to the create button at the top left corner and select "document". Here you can write down anything you want and use it any way you want to. You can bold words, select the size and font of letters, use color, and center the words.
In Google Sites you make a site. You can setup links to as many pages you want. Also you use tools like color, changing the font and size, change the background, and put pictures in.