Kindle

For Christmas I am asking for a Kindle. I have wanted one since I first heard about them from Oprah and now I am ready!
I have been looking at all I can on line, but I feel there is so much to learn.
I saw there were hundreds of free books for the Kindle and have picked out a few that I want. I have looked for some titles and found most easily. I couldn't find "To Kill a Mockingbird" so I am assuming that it is not available on the Kindle but and not familiar enough with the site to know for sure.
I also saw that you could categorized the titles you do have so that got me thinking about what is the best way to do that. Maybe area's like "classics", "sci-fi", "adventure", "Court's options", "children's", "romance", and "favorites" is the way to go... but we will see.
If anyone has one or knows a bunch about them that has some advice, I would love it. I can't wait!