A useful feature on the Kindle is the ability to organize your books into different collections. Collections are like folders on a computer. You can place books and documents into a collection to make them easier to find. This is especially helpful if you have a large library of eBooks. Unlike your computer, you cannot make sub folders on your Kindle.
Advanced Tip: I found it helpful to make a collection for all the samples I download and another one for personal documents. This freed up a lot of space on my home page. I went from 10 pages to 3.