The following is largely what I posted in another thread, but it really belongs here.
In FW2.2.0, Kobo added support for series. The database on the device now has fields for the series and series number. This is displayed on a separate line the library lists. So, there are three lines for each book that look like:
Series name - index
Searching will find the series name. Sorting puts the series name and index at the start of the title.
Unfortunately, there is no way to get a list of series. I would like to see a list like the shelves list that showed all series plus the number of books in them.
The other thing missing is a way to get the series info for sideloaded books. The epub standard does not include this information (unless it is in V3), so there is no standard way to get it to the device.
Some of the books from Kobo have series information. To see how it is handled, get a preview and look at the preview list. "A Game of Thrones" has it. Unfortunately, that still has the series info in the book title as well. I have seen some others, but I can't find them right now.
The calibre driver doesn't support this yet. I'm doing some experiments to work out how to do it without killing the performance.