I asked the same question a couple of months ago ("niceto have...") - no reply
The best I came up with was sortingby publication date - at least that gets them in the right order if not in series / sequence order.
The alternative is a pain - down load them in series order then sort by download date.
Having a series order is a great feature and one I want and would use, but unfortunately one we don't have yet, and most likely won't make it into the next major update.
Also we don't currently have the editing of metadata, so you can't change the titles within ADE. If you don't mind editing xml files, you will find all of the metadata (title, author, publisher, etc...) cached in the manifest.xml in your (My) Digital Editions folder. If you quit ADE, and then make a copy of this file (in case you make a mistake), then any changes you make should be apparent next time you launch ADE.
If you don't want to edit .xml files or just want an alternative besides ADE for organizing your books, I would suggest Callibre, with the cavaet that it will not work on DRM protected books.
Here's a work around that does not require editing of files.
It's slow but it works for me.
1. Delete all books from the library. BUT NOT FROM THE HARD DRIVE
2. Make a series of books shelves with the series titles as a reminder.
3. Add the books BACK to the main library in series order about 10 minutes apart.
4. Move the books to the series book shelves
5. FINALLY Sort the books by DATE/TIME
It's slow, clumsy, and BORING, but it works. (MOSTLY)
G L Heaton