I have mine alphabetically arranged on bookshelves. Then I have a notebook (an address book they sell for about a dollar at Meijer,etc-they are the size of a 2-year calendar) in which I have all my books listed-since I have purchased several twice! I carry the notebook with me since it doesn't take up much space. Each book has sticky notes on the patterns I want to try at some time or another.
I have another of the same type book for my purchased patterns-for the same reasons.
Yes, for some reason I'm anal about alphabetizing-I do the same thing for my spices whenever possible. Now if my sewing room could be as organized life would be great!