I was wondering if anyone had any advice on when the best time to work on Book 2 of a series would be? I am currently rewriting/editing Book 1 and have started plans for Book 2, but am unsure when I should actually start writing it. Should I start as soon as I have complete plans for Book 2 even if I am still editing Book 1? OR should I wait until Book 1 has been fully edited? Happy for advice from those writing a series, have written a series, or anyone else who wants to share their opinion on this
I have the entire series plotted, in general, before I start writing the first book. If you don't know where you're going, you're going to have a hard time getting there. After I write the first book, I set it aside and write the second, then go back and edit the first between doing the second and third, etc.
There's no right way or wrong way. In my first series, I wrote the books in order, finishing one before starting the next. In my second series, I wrote it all simultaneously.
Oh man, I really think you should finish revising book 1 in case you end up changing a few important things. Unless you're really good a plotting of course. I'm still new to plotting, so I've had to fix/improve a lot of things in the first edit I'm currently doing.
Something to consider is to write the first chapter or two of the second novel, especially if you're moving away from series/project. I say this because it helps keep a consistent flow in character, plot, pacing, dialogue, etc. However, if you're editing and revising book one, you're going to be very focused on all of these elements, so this is less of a reason to start into book 2. However, some people find it more difficult to stare at a blank screen (page) to begin a project. So, if you've continued the momentum when you feel it flowing, and get the first chapter or two of book 2 written (rough draft), then that makes the transition and beginning the second project easier. All of that said, to your specific concern, whatever works for you--whether to begin book 2 before or after book one is fully edited/finished. Some writers do better focusing only on one project, or are less efficient when they jump around within a manuscript, or tasks, such as editing. It also depends on your intended path. If you're planning, for example, to submit to agents (or directly to publishers), there is generally a wait time involved to get answers from those individuals. So, during the wait, you would have time to write book to. So, in that case, it would be more efficient to complete book 1 before moving on to book 2. If you're looking to self-publishing, the timetable is more in your control and the sequence of writing matters less. But, as others have indicated, if what you end up revising in book 1 affects what you might have written in book 2, making additional revision in book 2 that otherwise wouldn't happen...finish book 1 first. That's my two cents.