How do I keep a whole series in one place?

One file per book, or one for the series

In a word processor the usual answer is a file per book, kept together in one folder. It is the shape every book ends up in anyway. An editor, a formatter, and a retailer each expect one book to a file, and nobody downstream wants to receive the trilogy when they asked for volume two. The folder holds the series. Give it a clear name, number the files (01 The Salt Road, 02 The Iron Crown), and keep the series bible in the same place.

Separate files cost you in revision. Search, find-and-replace, and word counts stop at the edge of each file. Renaming a minor character across four books means four passes, and a phrase you suspect you have overused can only be counted one book at a time.

A single file fixes that. It also brings problems of its own. A long Word document with images can get sluggish, and one damaged file then holds every book. If you try it, keep dated copies of the combined file and split each book out when it goes to publication.

Google Docs has a size limit

A single Google Doc can hold up to 1.02 million characters, according to Google's help pages. A 100,000-word novel runs to something like 550,000 to 600,000 characters with spaces, so two books of that length can already exceed it, and a trilogy certainly will. Writers also report long documents growing slow to scroll well before the limit.

Split it. Put them in a Drive folder for the series, and use tabs within each book for its chapters if you like working that way, up to Google's maximum of 100 tabs. Google's help does not say whether tabs share the character limit, so do not count on them to get around it.

In Tabularia

A project can hold a series manuscript: several Books in order in one continuous manuscript. The Series starter opens with three, each opening on a title page and a first chapter, and Add another Book in Project Settings makes more. Every Book keeps its own title page, publication details, and page numbering. The Outline lists all of them, and find searches all of them while the scope is on Entire Series. The Working Scope narrows the canvas to Current Book when you want one book on screen, and Export lists every Book as its own scope, so each goes out as a separate file.

Sheets, timelines, and labels belong to the project. One set serves every book, and the series bible template maps onto it. Words are not metered on either plan, so a long series is not a problem of size in the way it is in Docs.

The trade-off is the one any single file has: everything is in one place, and one project is the thing to back up. A Cloud subscription keeps it synced and backed up, and also lets you export a project archive, a copy you hold yourself. On the Free plan, a DOCX export is that copy. Books kept as separate projects do not share Sheets.