Today I put up a ring of index cards on the side of the bookshelf FIC HIG. Each index card lists an author of a series (or part of a series) that we have here. For each author, there's a list of the books in the series in order. I've underlined the books we have here in the library.
This helps you because you can easily look up the book that follows the one you just finished. For example, if you just read Eagle Strike in the Alex Rider series, you'd see that the next book is Scorpia.
These lists are constantly changing as new books are published. If you know of a series we have that I have not made a card for, please let me know.