LibraryThing has added a new feature appropriately named "Series". Reading the announcement brought me back to my bookselling days when I created a notebook where each page contained a list of all the books in a series in publication order for all those customers who asked "which one is next?" Well, now the ability to to this is in LibraryThing.
To create a series, bring up the page for a book in the series and scroll down to the "Common Knowledge" area. Find the "Series (with order)" field and fill in the name of the series and the appropriate number in parenthesis. For example "The Monster Trilogy (1)". Do this for each of the books in the series. When you’re all done, users can click on the series name on the book’s page and get to a page dedicated to that series.
LibraryThing also allows for creating "multiple series" that a book can be associated with. Their example is the "publication order" vs. the "chronological order" for the Narnia books. [Note: I always read series in publication order. It’s the way the author wrote them and as a result later books, although they may occur earlier in time, will assume you’ve read the earlier/later-in-time books and make more sense.)