If you read books, you probably know of Levenger. Steve Leveen, co-founder of the company, has written a delightful book on how to get more out of your reading.
The Little Guide to Your Well-Read Life
If you like to read, and love books, I think this is a fun little book. He even has a term, book-love, for when you can't wait to continue reading a book. He writes "... living your well-read life is measured not by the number of books read at the end of your life but by whether you are in book love today, tomorrow, and next week."
The only thing I would add to his suggestions is to keep a shelf set aside for people you regularly exchange books with. It's much easier when they stop by to go find that book you thought they'd like than search through your shelves, at least if you have as many books as I do. I also have a special spot for "borrowed" books so I can easily return those to their rightful owners.