Gift certificate used

My brother gave me a gift certificate to Amazon for Christmas. I've sworn I would never buy a Kindle but I caved. I like actual books, however the library has many books only available as an ebook. This is why I wanted a kindle. I don't want to buy a lot of books and just have them sit in my reader. But borrowing from the library is a good idea. It arrived today and I've just set it up. Now to figure out how to use it...