Most books, if I think they are worthy of being read again, get re-read immediately. Then they are placed in any vacant place in the library, where they are likely to stay forever, or until I move. You are likely to find "Great Expectations" next to "The Three Little Bears". There are a few books, however, that I consult again and again. They get placed on a special shelf with other similar special books. This works for me.
Thomas
-Thomas